Well...I have gone through some sketchy places hunting on the web...still nada so far there...
BUT ...so far what I have dug out of our archives is ...
you can indeed run a different version on your 770 (he edition)...
synching your address book seems to be the only noticeable issue you can't do....from what is expressed by these gentlemen

ie...these gentlemen from post #3 down...

http://talk.maemo.org/showthread.php?t=11667

and actually the last post in there by boblinds...he states (that there was some conflict which was resolvable and so) running a garnet vm not even designed for his 770 was working for him fine.


Anyway..in the meantime....If I come up with some "eureka!" idea of locating a 770 specific copy for you...
I'll let you know...
regardless ...try the os2008 version and see what happens...worst case you have to uninstall it or reflash it at worst-worst...

and ..if you want the file specific for the 770 ...as bad as you say you do... get started private messaging members who were into garnet vm back in the day...
at least one of them MUST have a copy tucked away...