Is one of these the VIN? On your right you can see the hole for the brakes in the firewall thanks Tom
33-34 plymouth used the door jamb were the hinges are on bolt sides had 1 serial number and model number not sure about dodge and when they moved them
On the earlier Dodge trucks the serial number was on the left side of the cowl . On your truck I think they were on the right door pillar on a plate riveted on just above window crank level.