[Alan Brinton]

The first thing I would do is to loosen all those screws up and then work your way around the whole pattern of screws, slowly and gradually tightening each one until they are all fairly tight. Not too tight, but when they are all reset fairly well, see whether air is still escaping. If so, repeat the process tightening just a bit more. But don’t force the screws too hard, as the holes can strip and (if it’s a really old specimen) a screw can break in the middle.

If you completely screw down one screw at a time, you’ll get a less even seal.

It’s not unusual for the metal back of a Piano 36 to be hard to get off, Bruce. Doing so might compromise the gasket seal, but I don’t know how else you can figure out what the problem is. To take the back off, don’t start by trying to pry under its tight seal with a screw driver. Hold the melodica down flat, firmly with one hand, and jerk up on the handle, leveraging on one end and alternately on the other. Once the seal starts to release, you can carefully work your way around the cover prying gently with a tiny screwdriver. If you then take some photographs and post them here, those of us who have disassembled this model may be able to provide helpful advice.

Before you try to disassemble, though, wait to see what others here who have worked on the Piano 36 have to say. I personally would want to see what’s bouncing around inside (a screw?) and take a look at that soft note you mentioned to me, which might be a gapping issue.

This kind of thing can be very discouraging, but it’s par for the course for anyone who collects vintage melodicas. If you’re temporarily stuck, I can send you a loaner for the cost of postage or get it transported some other way. I’m in Boise.