Recently I bought two used tubes from a German seller. They were advertised as C3gS tubes, and the picture showed two tubes - only one had the pins visible - gold pins.
When the tubes arrived I realized that they were two different tubes, one with gold pins, and one regular silvery pins. In addition, they were not C3gS - just regular C3g.
I emailed seller, who said that they were compatible with C3gS, which obviously is misleading and not the same as the specially selected C3gS tubes.
Silver lining: Both tubes sound good and sound the same. When they are stuck into their sockets I cannot see the color of the pins, so I pretend they are the same. Since I have a pair of C3gS tubes I know that they sound pretty much the same - don't feel I am missing anything.
Unethical and misleading seller - yes, but not worth fighting about in this case since the tubes sound fine. And with a 10,000 hour life span I am not worried about them being used either.
Details about C3g – 1 Paar Siemens Röhren-Tube-Valve gebraucht gut /used good (=C3gS)
Caveat Emptor - Buyer Beware
The seller had very good feedback - didn't want to send anything negative back so I just didn't give feedback.
I am sure that once you get your adapters everything will sound splendid - IMHO I don't think you should worry about it.
Edited by mordy - 8/27/15 at 3:17pm