Thanks, Will. A mild sigh while reading it though because history seems to often forget Jack Hawley's role. Truth is he did not invent it, but he >>is<< the one that made them and got people to use them (the Xerox Alto's used a Hawley Mouse, DEC would use it, E&S used them etc.). As this article points out, he made about 80% of all the mice used in the 1970s:
https://www.oldmouse.com/mouse/hawley/ - certainly the first ones I used at CMU before we got the Altos and then after the first Alto's appeared.
Tek's Magnolia used a flavor of the Hawley mouse in 1979 [the ones with buttons horizontal/parallel to the 'body' - the original Alto mouse the buttons were horizontal and colored), but I don't remember what 3Rivers PascAlto used - I think so, but I don't remember.