Dave,
I didn't know the reed pan should be crowned--oops, I did meant convex! In answer to your questions:
The left side is pretty good... it's the right side that's the problem. You can hardly hear any of the real notes; instead when you push or draw on any key, or no keys at all, there is a uniform "chord" sound made up of many notes.
The valves are hardly twisted or curled, though I'm not sure what degree of curling is OK.
As you can tell, I'm a beginner but I'd like to tackle this.
Miriam,
its normal for reedpans to be a little 'crowned', that is the chamber side to appear to be a little convex, is this what you are describing? If so then it should not be a problem.
So lets get mote specific:
1. Which side is the problem side? Left or Right?, or if both which is worst? and is it only in squeeze and not draw?
2. are there a group of keys (notes) which are effected?
3. with no keys pressed, if you pressurise the bellows can you hear somme notes sounding? I.e. in Squeeze mode, if you de-pressurise the bellows by pulling (no keys pressed) is the instrument silent? please do not force anything for these two tests.
4. Are the valves all curled and twisted away from the reed pan?
Dave