I'm curious if you've bothered to take it apart and see what the deal might be. Are a majority of the plastic "rivots" in place? If you pop the stiff keys off, are the springs in good shape?
I haven't taken it apart yet, and I'm not sure I'm going to bother much with it. I'm not particularly interested in refurbishing it to make it usable--that's something that should have been done before it was sent to me. I'd feel differently if the keyboard sustained shipping damage, but everything arrived in pristine condition. If I've time this weekend, I may open it to take a look around, but after removing and re-seating a few keys, thinking they'd been jostled in shipping, to no effect, I just lost motivation and interest. I e-mailed Brandon about the 'board, figured I'd be returning it, and have since put the 'board back in the plastic wrap within which Brandon placed it before bubble wrapping and shipping it.
Of the two other space savers I've returned to him, they, too, looked pristine but also suffered the same stick/stiff feeling. The first was an 1989 white label, the second a 1992 blue label. This one, as I mentioned, is a 1987 white label. I've two other early 90s blue labels and they work perfectly. Who knows what's going on with the space savers--however, I'm inclined to believe Brandon when he says the quality and feel of springs within space savers varies--sometimes drastically.
BTW, I'd love to see some pics of your 'boards. (unless, of course, you've already posted them somewhere here)...Which reminds me, I suppose we should have a sticky keyboard picture thread, eh?
At the moment, the bulk of my model M collection is in bubble wrap and sealed boxes. I'm preparing to move in the next couple of months, and as things get sorted, packed, discarded and the like in preparation, I didn't want anything to happen to my keyboards. I've the 1988 1391401, which is my daily keyboard, and a 1989 1391401 wrapped in bubble wrap, sitting in a remote corner of the room, with a black 2007 Unicomp space saver in front of it.
As of tonight, here's what I have (all from clickykeyboards and Unicomp, direct):
the two blue label model m space savers
the two 1391401 model m 'boards
an m 5-1 with the trackball on the plinth near the directional arrows
a black and an industrial gray M-13 (the latter is made by Unicomp; the former by Maxi Switch).
three blue label model m keyboards--two with attached cables, one without
A 2001 rubber dome space saver II--black with red trackpoint; available at clickykeyboards:
http://tinyurl.com/2oeqvaa Unicomp Linux keyboard--layout 1--and a Unicomp black space saver
Sooner or later, I'm happy to pull them all out and take detailed photos. A collection photo thread is an excellent idea. My 1988 1391401, for example, was refurbished by Unicomp--the backspace key wouldn't function. When I received it back from Unicomp, there was a small sticker adhered to my keyboard's birth certificate: repaired by Unicomp, December 29, 2007. :lol: So now, the bottom shows the keyboard's birthdate and the date and company who resuscitated it. I'll get a picture of it and post it soon.
I really can't see parting with it. It's my most treasured keyboard. 
I respect your decision to keep the Unicomp-made space saver. If I had it, I wouldn't want to part with it either. There's no harm in asking.
I'll just hang around for the revision of the Mighty Mouse that Unicomp's supposed to make available this summer.
Cheers,
~rn.
