Hmm, there must be a good way to attach the keybed to a sheet of wood but I really can't come up with one.
This is how the bottom of the keys look.

There are about 20 plastic pillars that are threaded. I'd really like to drill through the wood and screw into the pillars but I don't think I can drill the holes accurately enough so that they meet up.
This was my first solution to the problem, attaching batons which are countersunk for the screws. Then I was thinking of glueing down the batons to the board.

It would work but I think it is a bit ugly and there must be a nicer way. Even though you don't see this part of the construction it would bother me to know that there was a nasty botch underneath the surface. Guess I have a perfectionist streak in me :)
Any advice would be appreciated!