Baldwin 46H

[rmontagna]

I wish to clean the key contacts on the upper keyboard of the Baldwin 46H. I know that there's a screw of some sort that can be accessed from the underside of the lower keyboard that will allow me to release and swing the upper keyboard upward. I've already removed each of the two blocks on either side of the tab assembly that allows me to swing the tab assembly upward, but I can't figure out the size or type of screw driver or socket set needed to release the upper keyboard. I've tried everything I have, but since I can't really see the head of the screw through the hole, I was wondering if anyone knows what it is so I can purchase the correct tool. I've uploaded a picture of the underside of the lower keyboard. There are two holes and I believe the one to the right (through the wood block) is the access point for the screw I need to remove. Thanks for any help.