One thing I'll say about these M13's... even though they're manufactured by Maxi Switch, they seem to be of the same quality as earlier Model M's manufactured by IBM. Unicomp's weigh a little under 4 lbs, whereas these, like earlier Model M's, weigh closer to 5 lbs. Further, there's no case creak, and the cases feel a lot more rigid / solid compared to Unicomp's. I also don't see any cosmetic imperfections on the surface of the case which I've noted with Unicomp's. I'll have to check for flashing around the key caps, but considering the boards I received were made in '95, I'm impressed. Like earlier Model M's, these make Unicomp's look like cheap imitations, in my opinion.
EDIT: Changed Lexmark to Maxi Switch.