www.system7today.com used to have some instructions on this very question. That would have been your best source, except that the link is not presently active: http://main.system7today.com/articles/leopard/index.html . Waybackmachine may be your friend here.

The fix, as I recall, involved use of the generic postscript driver on the OS7.6.1 (or 8 or 9) machine and enabling print sharing on an OSX machine connectd to the usb printer. I am not sure what else, except that it was said to work well, and that presumably printing would have to be IP-based rather than Appletalk-based. I do all my printing over Appletalk so can't help you there.