Back to 2.2.1 - yay! No Allmine yet, but baby steps.
For anyone who comes upon this thread later with the same issue, here's what worked for me:
1. ktwombley's "hellbent" golden dingo update. I am not finding a direct link currently, but I believe emusan's golden update will work as well for the same reason (removed checks) :
http://adf.ly/26dpT
2. vicinc's 2.2 ermine update 1.02 :
https://www.mobileread.com/forums/sho...d.php?t=141833
Still, for some reason, no luck with any of the other (stock or otherwise) update files. I get to the third white dot, and then a restart. Ad infinitum if I continue holding menu+rotate, or into currently installed OS if I stop doing so. Can any of you dev-minded folks see any reason this would be so with most roms (other than the 2 listed above)?
Filark, thanks for the tip - I'm downloading from the link you shared currently but still waiting. Sendspace is s-l-o-w. I'm not optimistic about this, but it's worth a shot. At this point, I'll be (mostly) happy with working ermine.
You guys rock! Special thanks to darkgrue, emusan, ktwombley, vicinc, and pablob for your detective work and development stuff I've come upon in other threads - without which I'd have no chance of getting this thing back up and running.