The only difference between the Chevrolet 47-53 fenders and the 54-55 is the area where the 54-55 grille extends a bit out from the radiator opening. Are you sure that you have a Chevrolet/GMC truck fender? I know that sounds like a stupid question for me to ask (and may well be), But either its wrong, or a poorly restored severely damaged one. Need some pics.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission