When I picked up the PC-9801 DO+ a while back, one included item was this SCSI board and RAM board joined to use only a single slot. It looks like it must have been a lot of work! But as the PC-9801 DO+ only has one slot, it's quite clever and beneficial. The workmanship looks neat and well done, to my amateur eye. I tested it to at least bring up the SCSI initialization screen, but I don't currently have anything to map the extended memory.

Unfortunately, I broke off the chip that goes in IC2 when trying to test it on another machine. I can't imagine it was there just for aesthetics, so I suppose it is currently somewhat incapacitated.