jtabler-
That may be a world record for water heater life...but don't count on it not failing...it's long overdue and may not be very efficient at this stage after all this time. I won't advise you on a replacement brand, but you should think about putting in a new one soon.

I suggest you look into a Marathon hot water heaters if you feel inclined to replace yours. They are lifetime warrantied and highly efficient by today's standards. I replaced an AO Smith that was 30 years old (tank never did leak) with one of the Marathons. You can shut the power off to one of those for a week and have hot water when you get back. They are well insulated. Many utilities recommend them and some give rebates if you install one.

I definitely question the efficiency. As for lifespan, for all I know, the former owners drained it every year and replaced the heating elements several times. Maybe they did nothing, but it's definitely a work horse! I realize that I'm living on borrowed time with this thing.

I'll check out these Marathon hot water heaters.