The Stovebolt Site Forums The Shop Area General Truck Talk What year is it?

I asked the same question on the one ton forum and LONGBOX55 suggested it was a seal. I hate to probe anything with a screwdriver for fear of messing up something unkown. But, I gently stuck a small screwdriver into a slot next to what looked like the face of a bearing and it actally moved when I put pressure on it. I worked the screwdriver around and popped out the seal revealing the large nut and locking nut behind. I.d still like to know what year it is. The rearend has a large raised GMC logo and ten bolts two of which are out of order. It looks newer than the rest of the vehicle and LONGBOX55 thought it might be a special order or even from a 1941 1 1/2 ton. The previous owner said it cruised at 55 mph?? It has 2000 ore. tags and was used as a movie prop and could have have had work done previously.