inner fender installation

[freds]

Hi, I'm rebuilding my 1967 Chevy and presently attempting to reinstall the inner fender and I'm lost on two specific corners. at the rear corner of the inner fender there is a 1" square hole that doesn't match to anything square on the fire wall that I'm aware of, now in the same location on the fire wall there is a bolt hole with a large washer but nothing square. now, someone mentioned something about " F-shaped " shims. how do they come into play ?. Second question, on the front end of the fender is it part of the radiators alignment hole ?. thank you