I was bored so I checked single-player machines around 1953 on IPDB and eventually found this on 1951 Gottlieb's "Watch My Line". Made sure to make sure the coin door layout stayed the same as the one on your picture through the years, went backwards in time as it seemed more logical that an older door would be parted out and put onto a newer machine, not a newer door onto an older machine, unless it was in the "collector owned era". It's a flipperless game.

Enjoy!

http://www.ipdb.org/showpic.pl?id=2755&picno=39145
http://www.ipdb.org/showpic.pl?id=2755

Doesn't seem to be registered on the Pinside list or I would link it to the thread.

I'm not sure on that one, sorry. What do you mean by unhinged, like you just take it off and set it on the ground? Sorry if that sounds silly if I'm incorrect, I'm a lot less familar with these older games, but that is the most reasonable thing I could think of.

The closest game I have to yours in my ownership is a June 1955 Gottlieb Southern Belle which opens like your standard coin door would if that helps any.

Here's a picture on IPDB.org of a Southern Belle with the door swung open like proper:

http://www.ipdb.org/showpic.pl?id=2248&picno=10632&zoom=1