@barliman2001 Exactly, I have understood it the same way, that it is a "pro trumpet" and that the higher the number, the better and more expensive. I think Yamaha should have 8000 and 9000 models too, but just like you, I don't know much about Yamahas. Thanks for the help anyway.

@Trumpetb said in Please help:

Word to the wise

On a conn of this quality and this age I would pay attention to protecting the lead pipe from red rot.

I dont think this instrument is suffering from this ailment at the moment but conns are susceptible to it.

Regularly running oil down the leadpipe and regular cleaning and maintenance of this part of the instrument should keep this instrument in tip top condition and playing wonderfully for many decades to come.