I'd suggest that you get another opinion from a different brass repair guy. Call around and see if the repair tech has a magnetic ball dent removal system. This is a newer approach than the classic one in which you have to disassemble the instrument in order to remove the dents. It works particularly well on large dents in large diameter tubing (like a bottom bow). I have used it myself do de-dent my 1924 Buescher tuba. I did this on the cheap by buying the appropriate magnet myself and just two steel balls of the size I needed. However, the entire system (with all the balls necessary) is pretty expensive, and not every repair tech will have it.
For a bottom bow (or outside side run of tubing) it can still be a little tricky if the dent is in the portion covered by the additional "guard" layer that's soldered on. In that case, the guard has to be unsoldered, the dent removed, and the guard soldered back on. But even then it's a lot less labor than the old disassembly method -- and it won't "change the sound of the horn" (though why a good job of unsoldering and resoldering should do that is certainly unclear). If the dent is NOT in the area with the extra guard, then just direct use of the dent ball and magnet can remove it in a matter of minutes.
So I'd ask around to see if there's someone in your area who could take that approach.
Gary Merrill
Wessex EEb Bass tuba (DW 3XL or 2XL)
Mack Brass Compensating Euph (DE N106, Euph J, J9 euph)
Amati Oval Euph (DE 104, Euph J, J6 euph)
1924 Buescher 3-valve Eb tuba (with std US receiver), Kelly 25
Schiller American Heritage 7B clone bass trombone (DE LB K/K10/112/14 Lexan, Brass Ark MV50R)
1947 Olds "Standard" trombone (Olds #3)