I just swapped the ms. pac-man PCB which came with the cab with one I already had. Reason: I hate the speed chip and alternative maze hack which are in Paul's 50's cabs.
I'm very happy with the cab, the cab is working, the picture is bright and the sound is very good.
The heavy screenburn is not visible during gameplay. Inside the cab was the complete manual and schematics. In the Pac-man and Galaga cabs I found this paperwork: