The Buttons & Controls board is labeled MusicTribe C003-01243-000, PCB403012REV01_01

You can remove the buttons and LED shrouds by unclipping the housings from the back of the board, being careful not to break them. I found using a spudger helpful. I wouldn't remove them if you don't need to since membranes switches are sensitive to contamination

There's not much on the board except lots of 74 series shift registers (74HC165D) and MacroBlock MBI5020 LED drivers. The rotary encoders appear to be six identical Dongguan LJV branded ones although not sure on the specific model.