You can really only argue that for one Kogswell bike, the P (the model that used your Artisan lugs uncarved...a look that never appealed to me).
The original D model appeared to be a model that Maxway already had drawn up, the F was a modification of the D for fixed gear. Neither were very derivative of Rivendell designs, in particular the 73.5 degree head tube angle and 38mm of fork offset aren't like anything Grant has built (and was very different from later Kogswell designs). These were sold for incredibly cheap prices and probably resale used now for more than most people paid for them new.
Here is the Kogswell D58 drawing, note the date which predates Rivendell by a couple of years and Kogswell by almost a decade:
http://phred.org/~alex/pictures/bikes/kogswell/d58.pdf
The P was pretty much a Rivendell Ramboulliet copy.
The G (a half TIGed, half lugged fixed gear frame), mixte, and various versions of the P/R all went in different directions. I'd argue that it is still difficult to find mass production bikes like any of them.
The most successful Rivendell copy of all time has to be the Surly Long Haul Trucker, which is an almost exact copy of the Rivendell Atlantis, minus lugs. That's now been copied by other companies too, but is different than most other touring bikes that have been offered. The overly stout tubing, huge tire clearances, 26" wheels for smaller models, and geometry are all different than the other production options that were on the market in the 80s and 90s.
I'm not a huge Kogswell fan and had some difficulties with Matthew Grimm over the years, but I did want to set the record straight.
alex
The emphasis on sturdiness makes me wonder about the tubing they'll use, and what geometry.