Interesting. The whole netatalk (on linux) thing is what got me thinking about this. I dont suppose you tried booting your IIgs from the Linux box with your ethertalk/localtalk adaptor did you? I notice that netatalk seems to support apple II boot.
I suppose this approach (the adaptor) would work with an Apple II series workstation card as well? I think I'll go google localtalk to ethertalk adaptors
Cheers,