I purchased a Henry 2K Classic from a ham friend that was moving and scaling down. This amp has been sitting for a while but is very clean. I have had it for a couple of years, but I have not fired it up yet. I removed the tubes to check them out and they are very nice Eimac 3-500z tubes showing very little or at least very gentle use. One of the tubes that litter my looks to be almost unused has what looks like a small internal fracture. I was considering removing the anode power on the tubes to do a gas test on the tubes to make sure the tube is still maintaining a vacuum. Is this tube safe to use? Is it more likely to fail and possibly damage the amp? See attached images. The glass on the outside looks to be intact and feels smooth. If the gas test does not reveal an issue, Is it safe to use this tube? Any recommendations would be appreciated.