The compressor was working fine, so I took apart the compartment with the freezer fan, and lo!  the freezer fan was iced over.  I've chipped it off and the fan is running.  If it continues to work, I'll do a complete defrost later.  I think I may have dodged a bullet.  Keep your finger's crossed. 

And sevenmpls , if I don't need that fridge you offered (and I still might), I'll still buy you a drink (I'll probably see at Minicon, if not sooner) just because you were kind enough to offer help.  I really appreciate it.