I studied trumpet at Paris so long ago that Maurice Andre was our mentor. At that time in the late 70s many of us bought (and still have) the relatively inexpensive Yamaha ytr-232.
It's history was -
Nikkan company copied the last developed Mount Vernon Bachs, under Vincent himself in the mid 1960s.
Yamaha after Nikkan had produced these improved Bach copies, bought the company.
There were three models, the T1 to T3, similar components, different weights.
The T3 was then named Tr232, and presumably because it predated the Schilke partnership they were promoting, it was unfairly called the student model and renamed YTR-232.
The 232 had a very limited period of valve material issue (some10% of total made), easily fixed but much made if it by other manufacturers to damage the major threat to their businesses by brass companies worldwide. This propaganda seems to have worked as it put many people off this classic.
I tried a Yamaha, Bobby Shew, lightweight, same size bell a few weeks ago. Eyes closed, I could have been blowing the same horn. No finger loop on the first slide and other cosmetic changes, but blowing wise, very close.
I have never seen or heard a negative review of the YTR-232, it's 'replacement' in number range was a true student model whilst the 63xx series held more in common with the 232 in the reshuffled range.
There must be many great 'sleepers' in old horns that should have higher recognition, but find one of these, blow it with an open mind, blind play it with newer models and I would be interested in your thoughts.