Clover, thank you for the laugh, unfortunately at your expense or rather that of your, 'friend'.
I rolled many of these tubes when i had a SEX amp. They all seems to be made by one or two companies and relabeled. Look for tubes with black plates on both plates. I had one tube with a grey plate and a black plate, that was an odd one. The Tung Sols sounded nice but the relabeled Conn tubes sounded just as good. In the end for some reason to my ears the tubes with black plates just sounded a little better than the others. I didn't try any of the coin based tubes.....