I made full technical descriptions and a lot of images of each cart when I submitted the rom dumps to mame. I wonder if they ever bothered to archive it anywhere.
FYI there are 3 different board layouts depending on configuration. There's the on you posted, one with space for an extra ram chip on the back, and one that uses SOP ROM chips + 2 ram slots. Some cards come with 1mb ram, not just 512k like most.
They kept updating the card software up till 1998...