Prototype set is here

[miniman82]

I do believe the stamping said D205, but I could be mistaken. I'll have a closer look when I get home, and photograph it with my macro lens. I'm assuming all the talk of pin counts is important because as development progressed, the 20-pin 15GP22 was the ultimate result? So earlier on they were using different basing if I understand this right, which would place my tube later on in the development timeline and peg tubes with different pin counts as earlier ones?