My comment was in regards to which pre-1960 trucks had painted bumper bolts. Chevrolet Advance-Design (and GMC New Design) 47-55 trucks are also pre-60 and they did not have painted bumper bolts.
Does this also apply to trucks with painted bumpers? That is, did the '53 models (with grey bumpers) still use the stainless-clad bumper bolts?
