I've seen stranger things done to cars, regardless of the original value. I still think it's a custom conversion from either a sedan or one of those truck chassis, and the grill is not from a 1953 but from a 1959 to 1962 'b' or 'c' series Ponton. The hood looks like someone modified it from a 4 cyl Ponton and eliminated the air vents. The bumper looks fabricated too.
I noticed a red 4 cylinder 'b' or 'c' series Ponton in the backgroud of one of your latest photos. You should compare yours to that car - see if the overall body measurements are the same - length, width, height, and compare other details such as the way the hood mounts and any other mechanical & chassis differences.

Happy Motoring, Mark

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