Shareway IP Standard or Professional running on a bridge machine solves these Appletalk problems, though it cannot get anyone 'online' in the usual sense of the word. It also costs serious money....

I gather that a cut-down version of Shareway IP was licensed by Apple and used in OS9 to allow the OS9 machine to accept personal file sharing connections from machines running Appletalk over IP. The full product is much more powerful.