This last
thing I need help with.  It looks to be about 20+ years old 
 but I could be wrong...
It is bright red, almost perfectly round, has
 a steel ball as the roller, 3 black switches, and says "5271" and then
 "DEPRAZ - MOUSE" on the bottom. 
 
That mouse model was used with the AT&T/Teletype 5620 DMD terminal, the
commercial version of Rob Pike's "BLIT".  Probably used for other stuff
as well.