Gozur,
no I dont have a spare capcom I/O - however, fingers crossed tommorrow i will have obtained another sega I/O and PSU, if so I will have a spare Sega I/O & PSU to power Naomi motherboard & a wiring harness for the I/O and GD Rom drive, that and the G - BIOS is everything you would need (besides the GD drive/Dimm board itself) to upgrade Naomi cart to Naomi GD