The Impqala is a bit of a mistery, appears to take the thumb lever catcher, but theres no bar (or space for one) on that door for it to vatch onto, nothing like the VC-160 type, and seems to have the remains of the usual black post to lift the flap inside the catcher.
There is a difference to the door flap on the far side, the extra indentations on that top left corner look unusual to me, maybe a latch caught on there?