Thanks so much for the ideas and theories. I think it is rust, the face plate and pressure bar had a bunch, but I'll wait for the ceramic lube, before I get much harsher, especially since the screws in the linkages aren't letting me unscrew them.
I've cleaned, got the Dremel out, figuring that might vibrate things a bit. And because of that great comparison link that Tammi posted have switched to trying liquid wrench, which seems to leave a foamy residue... Been wiping that off before reapplying.
I don't have a torch, but maybe I could try my heat gun... just concerned since the needle bar is a hollow one that it'll be more likely to break.
Thanks so much for all the posts, it's been getting past the point where I've been wondering if I was missing something obvious...