I know that a few people have done it. I've not heard that there's any difference in sonics. It's the same parts, made on the same tooling, just in a (slightly) different bottle. Mechanically, the bottle is all glass, so if there is any effect of bottle vibration, it's probably more similar to the coin-base octals - which some find to sound a touch better.
The hard part is finding the sockets; NOS supplies have kind of dried up over the last decade.
