Today I removed the base from my "beautiful" Russian GMI-11 tube.
This was to be for my next linear amp. The glass is cracked across one of the pins!!
It is extremely unlikey to have broken in transit, it was very well packed, mounted in its base and
the carton was not damaged. The glass on the base seems about 1/4" thick, it's rugged.
The socket pins are floating relieving stress.