I know a guy who can give you an exact value and will ask all the right questions, particularly if you are in the U. S.!
His name is Gene Gast Ph. # 563-355-8484 Call on your cell phone to avoid toll charges!
He does run a repair shop, and is a Juliard grad. Teaches Brass at the local university. Evaluates horns all the time
call between 11 & 5 cdt
I'd give my left *** to have it, but don't have any money right now.