... the same era cars had locks on both front doors, and other makes of trucks had'em on both doors, so it wasn't "industry standard".My take on this was that cars were taken to town way more than trucks during that era. Trucks were considered farm vehicles that were probably rarely locked anyway
if the keys were even taken out. Thus, the only time locking the truck might be necessary would be a trip downtown, which put the driver curbside. Just my conjecture.
