In 1993 I made three doors like that for our upstairs bathroom. Mitered corner, frame in panel, construction. Ten of the twelve joints are just as tight as they were when I made them. The two that failed were both on the hinge side of an 80" door. A door which I wanted to divide in half, but was over ruled by the "client".
I think I got lucky personally and that it's only because they are in a bathroom, that they made it. The swings in humidity are much less than other parts of the house.
It's impressive for sure that the table lasted that long period, let alone with that type of top, but I would have to believe that the wood was very carefully selected. The ends were sealed with whatever they had back then, and whomever made it was a heckuva craftsman.
I think that the math would suggest to construct a different type of top.
Last edited by Mike Cutler; 08-20-2018 at 8:13 AM.
"The first thing you need to know, will likely be the last thing you learn." (Unknown)