You are correct, the total would be the entry coin door and the cashbox, which would give you a working coin door. The only thing I am worried about is that the harness is the mounting system for the coin door to the body of the arcade.
As always, happ and any company for that matter will not include wiring. The wiring for the coin door is very easy with the exception of whether the bulbs need 12 or 14v. There are a ton of tutorials online for the wiring, but for us we have to make sure that we have all required parts first

. Wire gauge I am unsure of, but I will find out.
I checked out the exploded view and everything you need is in the price of the coin door.
This includes the lighting needed with a simple connection and ground spot. It also comes with cherry switches to connect the coin door to your arcade controls.
Looks easy enough

Any more questions just ask