As I read the OP, he's not saying they 'sound' warmer, he's saying they "run much warmer", and I'd probably give Frank a call about that. I doubt that there should be a noticeable difference in operating temperature between different versions of the same tube type.
I understand what he was saying about the temperature. The discoloration of the tubes are normal. It is called Getter Flash and is a sign of normal operation. It can be silver, or dark grey to almost black. White is a bad sign and indicates a leak. Also, different tubes will give off different amounts of heat (the 6CG7's do seem to run hotter than the 6N1P's). But I agree, to be safe, he may want to talk to Frank.
I was just throwing out some info about the sound of different tubes as I have the same gear (eventually given to my son) and tried just about every version of the 6CG7's and Sovtek 6N1P's that are out there.
Just a word of advice, do not handle the tubes with your bare hands. Skin oils will get on the tubes and create hot spots and they could decrease the life of the tubes. That may also account for part of the smell. If you do handle them, wipe them off with a clean rag.