"Technically do I have a 51 or 52?"
Well, it depends on which technicality you adhere to.
If the VID plate on the driver's door jamb is the original plate and it indicates 1952, you have a 1952 truck.
hotshoe36's theory seems reasonable and it is certainly possible. Look at it this way, you'll have a good time explaining this to people who might be interested in these sorts of discrepancies.
