Sooo, I think the Tandy 1000 PLUS-ISA Riser v1.0 board is done - space is a real issue so I've made the following compromises:
1/ There is less space between the bottom slot and the middle slot - the idea is that a very slim card like a Lo-tech ISA CompactFlash IDE would go on the bottom.
2/ The middle slot would be ideal for a slightly thicker card like an original ISA Serial Card
3/ the top slot would be ideal for a slim card like a lo-tech ram card that doesn't require rear access.
I'm happy to entertain others opinions on this design as I wont be needing one myself.