I got the LightFight. This one has a National Semi COP421L, with additional markings HLA/N /B119. The COP444L from Entex Space Invader was marked HRZ/N /B139, so I'm guessing HLA/N specifies the ROM contents and /B119 is the date code. I should be able to electronically dump this one, although I might have more difficulty finding the start since it has less ROM space and therefore probably has less unused space, which helped me with Space Invader.

Worst case, I'll have to force opcodes to start the dump at 000. Now that Kevin found the errors in the app note, that'll be easier!