Fb, i appreciate your adhesive advice, but i'd rather not do something quite so permanent on a crank, even if the thing is essentially doomed anyway... It'd probably work for someone with less OCD than I got.

I removed the right crank, took off the granny, and inspected the threads. The threads appear to be intact only a few mm down from where they begin. However, they seem to be damaged at the point of engagement: cross-threaded, i reckon. I may be able to retap it, but i bet a good tap would cost more than the cranks are worth.

I'm thinking this crank may live on, in a future single-ring project. I've got another one of those on the horizon...

My travels on the interwebs has led me to ebay, where i got a new/unused rear/right sugino xd tandem crankarm for $1.99. Of course, this is ebay, so it'd $13 shipping. Still, $15 is less than half of what everyone else gets for 'em online. Next time i order from treefort, i'll grab the left arm for $17. Use the biopace rings on the XD. Practice my polishing skills on the semi-stripped deore crank while i scheme on my next project.

Thanks for the help, guys. =D
-rob