I have one of these. It uses exactly the same parts as the top half of an over-under coin door. The only difference is that there are no mechs, the return slots are blocked from opening by a metal bracket, and the coin slots have full length plugs to prevent coins from being placed inside. The reject buttons do depress. The door comes with a key and it does open and lock.
I bought mine because I wanted a smaller door for my cab, and already had a full-size pinball door so didn't want to pay full price for parts I already had. I actually swapped out the coinslot plugs, removed the brackets from the return slots, and installed the coin mechs from the other door. Everything fit perfectly.
I think you could get the same results by placing a custom order with Happ (order the fake door with mechs installed). I also don't think the coin mechs cost much, so you could get them separately too.