Went out and looked at my 58 and it has 2288 in grease pencil right above the battery,just above the firewall & cowl panel seam.The area where the number is on your truck ill have to wipe the years of dust off mine to see if it has numbers.Not to stray from the bolts but a buddy of mine is a big mopar guy and he said there have been numerous cars that have had signatures of line workers found under the rear deck upholstery.
