What happens when you power up the old MPU board, does the green LED flicker and flash (if yes how many times)?
Can you post a clear closeup picture of the chip at U8? It looks to be physically damaged in you picture.
The board appears to have the Silverball Mania program ROMs which is good, and not Dolly Partons (the picture is not clear enough to 100% confirm)
ROM chip at U1 should be marked "E-786-16 U1"
ROM chip at U2 should be marked "E-786-17 U2"
ROM chip at U6 should be marked "E-720-35 U6"