I see its nosed, doesn't appear to be decked, and other than a paint job it doesn't look like a custom to me. Is there more to it than nosed and painted? Sorry, I have never seen it before.
of course its decked and it has 51 bumpers and headlite doors. Bumper overriders are removed. The Ford crest has been removed front and rear. The Crestliner script has been removed. Its a mild custom. The mirrors will help identify it. Someone may know the builder. It hasnt been driven in a very long time. The tires had rotted off.
The deck lid looks stock to me, minus the brim that houses the license plate light, trunk handle and lock. I'm sure you know more about it than me, though the pictures and shadows ain't the greatest. Mirrors look like the average late 60's early 70's American family car variety.
The large 1/2 circle indent for the license plate to be filled in? I suppose removing the brim and filling those holes may suffice for some. Look man, just trying to help you out, not trying to downplay your car or anything. Provide some good pictures so we can see what YOU see.