This has come up before. Apparently some states used the date of registration rather than the manufacturers year model. A lot of states didn't issue titles back then.

I don't believe that is the case here though. Since the cab has a side vent I'd say it's a 50 that has had the doors swapped.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.