in 43 the OEM serial number was not stamped on the truck anywhere, only on a metal tag [on the pass side cowl in 43?], but as Bill sez, the normal deal back before the mid 50's was to use the engine number on the title as the "vin", you'd find that on the machined pad to the rear of the distributor ... the fire body may also have had a makers tag somewhere that could have a confirming number and/or date on it .... if you have a previous title with a "vin" on it the form of that number would be a clue as to what was used -
see here for the body serial number format
Bill
