How can you tell if it is a true SWB 4x4?

[pryorstemmed]

Hello, looking at a 71 SWB (badged)Cheyenne 4x4. It does not have a SPID and the seat has been recovered, so I doubt there is a build sheet there. The frame has been painted black. The vin starts with CKE141 so it is a 1/2 ton. I have not checked the vin on the frame yet, will that do before I buy. It also has a 350 that was stated to be original. Is there anyway to tell if it is a true SWB? It has Cheyenne emblems but the interior has been customized, so the door panels and headliner are not original. I remember a thread that said to check the holes for the headliner and look for factory oval openings. It has the rear cargo light and a chrome/stainless tailgate handle. Any other things to look for? Thanks for any help guys and gals.