Really old.I think they are old "kit form" altimeters by Transolve.
I dug out the bag of Parts out in the garage and it had the instructions in there along with the altimeter parts. The instructions are in there and what I have is a scratch-built RRC2 collection of parts. Apparently missile Works published instructions to build the altimeter. I don't know if what Tony has is someone's iteration with custom circuit board or some other device. The missile Works instruction show hardwiring on perf board. A date on the bill of parts said 2005. KurtNot a P6K. They're not that. I think there was a kit in the way bygone days possibly by "Gee Wiz"? A fellow gave me a bag of parts that had a construction article in it the he never started or completed. I'll pull it out as I have the article still in there.
It was a kit version of a commercial and updated design the came out later. When I get home, I'll find it and report back. The thing here is the builder was to consider perf board hard wiring and the picture above looks like a home made or
low production single sided PC board. Kurt