Hi. I pulled apart an older Casio keyboard to check out the key contacts (it is equipped with MIDI sockets) and found an array of plastic covered switches that are activated as the key is depressed. If you study the geometry of this tpe of switch, I can't see why a couple of small screws, mounted under the wooden keys of the reed organ, couldn't provide the identical activation (part of such a keyboard would need to be installed inside the casework below the keys, of course). Certainly these older keyboards can be bought for just a few dollars and if you go slowly, you can't do any permament damage (just treat the LSI boards with respect).
Good luck, it's fun experimenting.