My personal opinion: I would not restore this cabinet because it is missing so much and you are a newbie.
Mame it? I would say yes, but most people on here would most likely disagree with me.
You could mame it but keep it as is, so that it can be restored someday (perhaps by you), but it looks to me like it needs a lot of work to make it original.
You might remove the control panel and store it away some where so that you dont ruin it by adding more joysticks and buttons.
I would also offer the guy 25 shucks, because it doesnt have a lot to offer, and it needs some panels, coin door, etc, which you will have to buy, cut, paint, etc.