I cannot provide any evidence (other than circumstantial) of those two
being fakes or not, but I would not be surprised if they were in fact
GUI hacks. The image I removed them from was highly buggy. It was a
french System 0.97 disc (I think). It took hours of work to even get
them extracted. SwanSong was the only typeface that did not immediately
work when trying to import the modified resource fork file into
FontForge; I had to do some extra hacking to get it working at all (the
difference can be seen between the original [Originals/System 0.85
Fonts] and the modified [Originals/CairoSplices/Swan Song] versions that
I could import into fontforge).
I also noticed that 10-pt version of Chicago (which is actually the
standard 12-pt). I really have no idea. The design of both typefaces
seem similar to other work Susan Kare has done, but without contacting
her/Andy Hertzfeld I really don't know if we can have any resolution.
The only thing that makes me question whether this is a "hack" or not is
the fact that someone has one of the /original/ Macintosh 128k's, and
his machine has both of these fonts installed on disk (which makes me
question about the whole tampered-with hypothesis). I doubt this GUI
hack made it's way into France as well as the US.
http://facstaff.cbu.edu/~cyelving/Mac128.html