IMO that is too expensive for a Galaga restoration candidate. The price reflects the multi-game, and since that isn't what you want to do with the cab, that's is expensive as a base price for a restoration.
As afr as your question, you'll need the artwork you pointed out. The coin door isn't original either. You'll have to find out if the insides (wiring) are JAMMAtized.
1. Are the internals JAMMA or is an adapter being used?
2. If the internals are JAMMA, it won't be original, but you could just buy a Galaga PCB to jamma connector.
3. If an adapter is being used with original internals, then you'll just need Galaga PCB.
In any event the price you will pay for what you need, added to the 650.00, makes this cab way too expensive for a resto IMO.
Others may disagree though.