One of my places had a water heater dating back to 1950 that I
replaced in 1995. The A.O. Smith replacement only lasted 7 years
before leaking.

Thanks for another A.O. Smith data point. Seems like 7-10 years is the
magic number.
I am now leaning towards replacing it since:

1. This is an A.O. Smith water heater manufactured about 1993 -- about the
same era as your unit which failed.

2. I had a similar A.O. Smith water heater tank fail in my main home in
year 2000. IIRC it was also manufactured in the early nineties.

-- Paul