It looked like there was enough there to make a viable instrument out of, and it looked like both were Conn, so when I got offered a deal from the seller, I took it.
The extra valveset was from a different era than the existing valveset on the horn (horn = diamond flanges, extra valveset = round flanges... I forget off-hand which one is older), and I couldn't just drop the extra pistons in -- diameter was slightly too large, so I decided to swap the entire valveset out instead of doing a bunch of lapping. Some parts were juuuust different enough that quite a bit of fudging and futzing had to be done. There was no 3rd valve slide on the donor valveset, but there was one on the original horn, and the distance between the tubing legs on the original slide was slightly too small for the donor female tubing, which meant that the crook was all splayed and not parallel. I had to trim some braces to get that alignment correct. The taper on the tube leading from the 3rd valve to the small end of the main tuning slide was also different, and the small end of the existing main tuning slide would not fit in the donor valveset, so I had to pull that tapered piece from the original and paste it on to the donor. After quite a bit of fussing with braces and getting slides parallel, I finally ended up with a viable and usable instrument. Less than $100 and a couple hours in the shop, not too bad, and I am generally pleased with the result. I will sell this horn to a local middle school after I get a case for it.
