Can anyone shed light on these tubes? Any info would be greatly appreciated. From V1: This tube says "Pro/Comm" on it. Never heard of that badge, but I'm guessing the "Made In Germany" can help someone identify it. Approximate age or other name brand equivalent? I assume that bent pin on the left photo is a bad thing... V2: There's just about nothing left with which to identify this tube. There's a small amount of orange paint left right in the front there that looks like it used to say, "Made..." or something like that. See that M? V3: Obviously branded "RCA" and it says "U.S.A." Can you tell me anything about it - Longplate, short plate, ribbed, blackplate, etc. Thanks in advance.