I picked up a 53 F100 that was pretty much in pieces and am in the process of stripping paint from the doors. There is a rectangular hole 1/2" x 1 1/2" on the outside surface in an area near the top hinge, can anyone tell me what that the hole is for? It is in both doors.
Thanks

 

I think you're looking at the holes that the mirrors go in. Two bolts hold them in place. the bolts go in through the holes in the front door edge panel. If you have a Service Manual or a Mid-Fifty's catalog you can get an idea of how they attach.

 

Definitly mirror post holes, go to galleries, select 53 in the year box and you will see how they are mounted on my truck, send me a message and I can send you a close up picture of mine, as my gallery says I have a 56 cab on my 53 chassis but the mountings are the same.