Well I have just tested saber wulf disk image on my TI and it ran fine so my nano peb memory must be fine like you said.
I got the board assembled from arcadeshopper.I'm using 27©040 eproms
One thing I'm not sure about is the jumpers.I followed the instructions for the 27512 (jp2,jp3 (1-3) and jp4 (1-2)) but left the other jumpers as they were so jp1 has no jumper at all,jp5 and 6 are jumpered,jp7 has no jumper and jp8 has the middle two pins (1-3) connected.
Will have a look through my spares and see if I've got a 74LS378 lying around and give that a try as looking around the board with my magnifying glass hasn't shown any problems with shorts.
I have only tried two games from the 512K compilation that you posted with the memory test that worked for me and the correct games appeared that I selected.Will try some others to see if they all work.