Old Time help on water heater

Would love to keep our old 'National' water heater made in 1962. Works great. Have to move it to new location. Concerned about it not having a pressure relief valve. Have seen the 'Myth Busters' episode before! It gets fed with cold line from below and out the side on upper section of tank comes the hot.I was wondering if there would be some way to ad some sort of valve on the hot water pipe exiting the tank, but wouldn't the complete hot water system get the expansion if it were to occur? Wouldn't it just bypass the valve? It seems such a waste to scrape the old lady. National Steel Works was the maker out of Seattle Washington. I have heard that AO Smith bought the company. Any info would be helpful or helpful suggestions please.

The T&P valve needs to be inserted directly into the top 1/6 of the tank, not in the piping off of the tank.

I would send it to a museum and install a new water heater.