Last month’s ware was internals from a VCH-1006 passive hydrogen maser. KE5FX has published a great write-up about the unit, its history, and how it was repaired.
I’ll give the prize to Hessel. The guess given was about as close as anything I could have done myself — a pretty challenging ware, as I’ve never seen anything quite like this before. Congrats, email me for your prize!