Mike, I have looked at this gun for several months. I just assumed he inserted an "X" in the serial number so comeone could not claim that gun was stolen from them. The few guns of this type that have serial numbers (I have only 4 with serial numbers) can be verified with a factory letter from Mr. Callahan, who has all the old Savage/Stevens records, so the owner could have gotten the 1948 date from Mr. C. Or, there may be a date code on the gun. As example: 11A in a circle could mean January of 1948. There are still lots of unknowns about these date codes. The gun itself appears to have been re-blued and left in the tank too long. Did you notice the cherry color of the receiver. I have not found any indication that the color case hardened receivers were ever done at Utica. Perhaps he is mistaking the cherry color for color case hardening? One of my guns has a serial number of 5021, so I think the 4 digit numbers are valid. I have a factory letter on all four of mine with serial numbers. I would not be interested in the gun because of the refinished metal. Also, I cannot see a serial number stamped in the lower left rear side of the frame, where all others are located. So, it could be that the number he gives is not a serial number, but an assembly number, something like "4" over "OX3", and is just guessing at the date. As well as I can determine, by 1948, Savage had moved to Chicopee Falls. But, just like with Colt and Winchester, I would never ever say "They never did that."