I have an old Yamaha Geyer YHR-861 that I played professionally for many years. I got it back in 1987. The lead pipe has a slight bend in it and there are dings everywhere... This was a terrific horn for me but I am afraid all the wear and tear has caused it to sound inferior to its younger days.
Should I consider refurbishing this horn or move on? How do you know when a horn has taken on too much collateral damage to be worth saving?
The 861 is a fabulous horn - I played one for almost 8 years. I'd say HOLD ON TO IT! They're quite desirable instruments - and unless the valves are leaky (which I doubt) everything else can be repaired quite easily. Small dings typically have no affect on how the instrument plays - but the rule of thumb is that if the dent is greater than 20% of the diameter of the tubing then it will affect how the horn plays.
(thus, a smaller dent in the leadpipe will change the feel of a horn more than a similar sized dent in the bell tail).
Have the work done by someone you trust - ask around - and enjoy that horn!!