I do not know for certain, but I assume that 1952-55st painted bumpers used bright (stainless-clad) unpainted bumper bolts.
The Master Parts book shows only one type of bumper bolt for those years. We can speculate that the assembly plant would not have had a bin of bright bumper bolts and a bin of anvil gray painted bumper bolts (or, white, on 1955-1st painted bumpers)?
