I had forgotten that the reed plates of the original Pianica 32 are also mounted on the inside of the air chamber cover.
I just made a bid on a Yamaha P-32B (1973-78), hoping I can pin down the change in where the reed plates are mounted. I have not seen a 32B before. Here’s what it looks like (this must be when, during the evolutionary development of the P-32, the first model walked up from the sea on to dry land): or (: