AH, looking at the pics again, it looks like you have already wired in a vend switch. That machine should hold 300 cans or 174 bottles going by the model number.
You will have to rig up some kind of replacement latch, since without that screw drawing the door closed, you will have a bad air leak.
That screw rod will come out, just held in by a slide in pin as I remember. The spring has no function as to actually closing and sealing the door.
Its there to allow for some "give" when you first push the door shut. Otherwise, when you push the door over the roller at the bottom, the screw can sometimes push the nut out of the housing.
J.