If he was the original owner you are correct. If he is not the original owner, it lasted long enough for the original owner. That is a 50% average. Do you think there are 50% of the original simplex Delrin derailleurs remain, well never mind that example.

I found out there is another chain stay available from Nova cycles that is 2mm thick.

Jim, you are the "they" because you use aluminum handlebars and that makes you one of the people who buy aluminum tubes "damn the torpedos". Once you let the cat out of the bag it's pretty much a matter of time before you find an Alan dripping with Campy and you too will be enamored by the glow of polished aluminum tubing but this time it will be attached to dropouts. Will it matter?

Only time will tell..