@oldschooleuph Even at the end of Mt. Vernon, the horns simply did not have the build quality of the "competition". That does not necessarily have anything to do with playing "well". Even a "bad" Bach had that magic core and adjusting to the playing characteristics was just something that we did back then.
The perception of the Mt. Vernons today is considerably different although the lacquer and valve issues are the two things normally necessary when refurbishing. Either the Bach lacquer was not so good or the horns were not prepped properly.
There is a swiss artisan Rene Spada that disassembles Bachs and rebuilds them with swiss precision. In my view, they are what Bach should have been all along. The Spada Bachs are simply that much better using only Bach parts. Even if I had a Mt. Vernon, I would have it disassembled, cleaned and put back together with Spadas precision and attitude. There are other artisans. I use one Rainer Jordan who has his shop close to Frankfurt.
I have had 3 Bach trumpets. A 180 B172* (new picked at Giardinellis in New York but rebuilt by Spada), a 180 B25 and a C229H (also bought from Giardinellis). I still have the 229 although in the mean time, it has been completely disassembled and rebuilt without tension as well as getting a tuning bell and a new leadpipe.