A good lot of the Autobots came straight from Diaclone with little to
no alteration. Blue Bluestreak didn't happen because Bluestreak was
going to be blue (well, that might have something to do with it) but
because they were reusing Diaclone artwork that already existed.
The thing is, there's a very specific subsection of the Diaclone toys
that actually had painted box art; a good half or so of them simply
had photos of the toy. At some point the paintings became cost-
prohibitive and were replaced by the photos, and then I think at some
point they were then re-instated when the budget got big again. You
can actually sort of piece together a chronology of Diaclone releases
from the box art alone (along with other factors)...and someone has
already done that:
http://www.tf-1.com/articles/pretf/prod_template.html
From this webpage, here's a rough listing of the release order of the
original Diaclone toyline along with what toys had a photo
representation and which got painted box art. (It's using Transformers
names as a shorthand; they obviously weren't released in Diaclone
under these names, and certainly not with names like "Red Sunstreaker"
or "Black Ironhide.")
No.1 Red Sunstreaker - [PHOTO]
No.2 Black Ironhide - [PHOTO]
No.3 Police Sunstreaker - [PHOTO]
No.4 Ratchet - [PHOTO]
No.5 Trailbreaker - [ART]
No.6 Honda City R/S - [ART]
No.7 Bluestreak - [ART]
No.8 Red Hoist - [ART]
No.9 Skids - [ART]
Blue Hoist/Silver Honda City S Doubleset - [ART]
No.10 Inferno - [ART]
No.11 Smokescreen - [ART]
No.12 Hound - [ART]
No.13 Prowl - [ART]
No.14 Jazz - [PHOTO]
No.15 Sideswipe - [PHOTO]
No.16 Mirage - [PHOTO]
No.17 Optimus Prime - [PHOTO]
No.18 Wheeljack - [ART]
No.19 Police Sideswipe - [PHOTO]
(DC)No.1 Camshaft - [ART]
(DC)No.2 Overdrive - [ART]
(DC)No.3 Downshift - [ART]
No.20 Grapple - [PHOTO]
No.21 Red Tracks - [ART]
Powered Convoy (regular and chrome) - [ART]
Powered Convoy DX set - [ART]
So this is the list narrowed down entirely to just guys who were
released as Transformers (in most forms) and had painted box art:
Trailbreaker
Bluestreak
Red Hoist
Skids
Inferno
Smokescreen
Hound
Prowl
Wheeljack
Camshaft
Overdrive
Downshift
Red Tracks
Powered Convoy
Even though some of these are "variant" colour schemes, they were
still, in some cases, reused for the TF release. Red Hoist was
recoloured and altered slightly to become the regular green Hoist we
all know, for example. (Diaclone's Red Hoist has a driver visible in
the windshield, for example.) These kind of minor changes are all over
the box art. Smokescreen, for example, was reused, but the Diaclone
box art had "DATSUN" markings and a few minor colour differences--and
obviously, things like Autobot/Decepticon symbols were added where
applicable. The Omnibots didn't have "proper" box art, but it has
popped up in some secondary sources; it's just the Diaclone box art
reused like normal. Powered Convoy had much different art than Ultra
Magnus (and IMO much better) so I'll remove him from the list. Red
Tracks did indeed become Tracks, however; it seems that by 1985 Hasbro
was much more willing to alter the box art, as evidenced by the
variant Shockwave boxes and the altered Tracks and Hoist boxart, plus
others like the Dinobots and Constructicons (more later). The
unaltered Red Tracks boxart was reused for the Red Tracks eHobby toy--
Road Rage, wasn't it?
This list also doesn't include other Diaclone toys like the
Constructicons, Insecticons, Dinobots and Seekers (Jetrobo), nor the
Microchange toys that became most of the Decepticons. I'll go into
these individually...
Starscream and Thundercracker are ganked wholesale from the Diaclone
box art. Thundy's pose was altered slightly so that he's less spread-
legged. (Honestly I think I prefer the Diaclone box art for him; he's
more dynamic and looks like he's about to pounce on an enemy.) Skywarp
didn't have a Diaclone release so his box art is a Transformers
invention.
The Diaclone Insecticons also had box art; this was similarly
recoloured for their Transformers release. The Diaclone box art was
reused for the eHobby "Insecticon Clones" reissue, which was just the
Diaclone colours.
I'm only doing a cursory Google search to confirm most of these, and I
couldn't quickly find any Japanese Diaclone Dinobots in-box, but I did
find some Italian GiG releases which tended to reuse the box art from
the Japanese releases; they're identical to the Transformers releases
except for colour differences.
The Constructicons also had box art, but it was obviously multi-
coloured to reflect their toys. Devastator's box art also comes from a
giftset, shown front-and-center. (I could only find one tiny pic of
it, but it's enough to verify.)
Onto the Microchange toys...it doesn't appear that most of the
Microchange toys that became the Minibots had box art; certainly not
Bumblebee, which must mean that the sticker shown on his robot mode
chest in his box art was going to be there at some point during the
Transformers phase. (Zob, you'll know more than I do about it;
Bumblebees aren't my specialty.) There were several different releases
of the Minibot predecessors, but they all appeared to only have photos
on the boxes; no box art.
The cassettes, though! Ravage, Laserbeak and Toy Frenzy (the blue one,
for argument's sake) had box art derived from Microchange; they were
actually all released in a box set together as well as individually.
Buzzsaw's box art is simply a recolour of Laserbeak's. Soundwave's box
art is straight-up Diaclone, but I don't know where Rumble (red
robot)'s box art came from. It's possible it was a Transformers
invention. I also don't know at what point the change was made to have
Soundwave's gun arm lowered, as opposed to pointing out further, but
it may have been 1985, when altering the box art was getting more
ambitious and more of an attempt was being made to show off the toy
itself as opposed to the artwork. (This is around the same time the
grey/silver "border" started showing up, right?)
Megatron's box art--both of them!--is also from his Microchange
release. Nothing new there.
So it might be better, instead, to list all of the 84/85 characters
who had no Diaclone/Microchange box art. I'm going to exclude anyone
who obviously wouldn't have art like the 1985 Minibots and the non-
Takara toys (Jetfire et al), mostly because it's obvious they were
done as part of another "batch."
Brawn
Bumblebee
Cliffjumper
Gears
Huffer
Ironhide
Ratchet
Jazz
Mirage
Optimus Prime
Sunstreaker
Windcharger
Skywarp
Rumble (Maybe)
Blaster (Had Microman box art, but it was radically different)
Grapple
Perceptor (Questionable--I couldn't find any pictures of Microchange
Perceptor's box art, if he had any)
Astrotrain (questionable--see Perceptor)
Blitzwing (see Perceptor)
There might be a few others, too, who didn't have an equivalent but I
didn't include them because this is getting unweildy.
I think the fact is you can probably separate them into groups of
Dudes Who Had Diaclone/Microchange Box Art and Dudes Who Didn't, and
then segment those guys and see who "seems" like they were done by the
same person. For example, a lot of the non-Diaclone Boxart 1984 guys
have a similar "one leg raised" pose, like Mirage and Rumble.
In fact, Rumble and Mirage could have been done by the same guy--even
Jeff Mangiat--but unless Jeff Mangiat was working for Takara in 1980,
there's no way he could have drawn Starscream's box art...
So I did a little more digging. (Man, this post is huge!)
Here's an interview with Jeff Mangiat, where he fesses up to, in fact,
drawing Optimus Prime, Jazz, Mirage and others. (He mentions "some of
the jets" but I'd be willing to bet these were 2nd gen guys like
Ramjet and Dirge; possibly Skywarp as well, and those weird Takara
half-repaint Seeker guys who are just Starscream, Skywarp etc. with
the Conehead wings.) He claims he worked on them "up until they
switched production back to Asia and the animation houses," which
says, to me, up until the back half of the series in 1987-88 or so.
http://tformers.com/transformers-interview-world-renowned-illustrator-jeff-mangiat-talks-g1-transformers/12545/news.html
Optimus Prime is a curious case, though, since his Japanese original
release had different box art. (Check it out on Botch's site.) It's
weird because the Japanese Convoy drawing is clearly an entirely
different drawing, not just a slight alteration! Mangiat's is clearly
entirely derived from the toy (down to being in a pose the toy can
actually do) and has some of his tell-tale bits (You can tell his
hands, because they always have a ton more segments than most of the
clearly-Japanese drawings. Perhaps Takara didn't like Mangiat's
Optimus Prime for some reason, and had one of their in-house guys do
their own version.) Interestingly, the Convoy drawing seems to have
been drawn with the Autobot symbols in mind, while Mangiat's Optimus
Prime seems like they were slapped on by a different artist...
I'm tempted to say that all the non-Diaclone art for 1984 & 1985 was
Mangiat, with Richard Marcej doing most of the 1986-1988 art. So...I
dunno!
But a good bunch of them are Diaclone art.