WOW! Absolutely incredible job putting all of this research together, and piecing together the evolution of the J100. I can't wait to dig into it more thoroughly. Truly impressive work! Thank you, Matt.
Added a few more J100s to my collection, so I figured I'd post an update.
(Also, I'm still interested in acquiring more, particularly the Plomb-era ones, so let me know if you're selling.)
Here's my current J100 collection as contribution to the project! (Most are blank on the back. The oldest one says "MERIT PLB.SUP.Co K.C.Mo." on the reverse.)
Also, I'm interested in growing my collection, so if anyone is looking to sell their J100s (particularly the Plomb-era ones) I will...