Digging up this old thread because I need to replace a line filter on another System 80 game. Looking at the filters from Rockby, the 20A one is cheaper than the 10A. Is the 20A better?
Should I also add a MOV and a thermistor to the game? It didn't have one originally. Has anyone done this? If so, please post a pic.

Don't need a thermistor, although a MOV is a good idea. 20A will be fine. They probably have more 20A produced, hence the low price.