Picked this up near Boston for $50 thanks to a great tip here at the MLA!  It's a standard 512k with a 10MB Hyperdrive installed.  It's in really good shape, and boots up to System 5 currently, but I think it's probably on its last legs before a cap failure gets the best of it.  I'm just excited to have a real 512k in my possession.  Anyone have any idea if the backspace key could be fixed without replacing the switch?  The switch itself functions, but the stem is busted off the top and I'm always wary of soldering...