jerry thomas said
I have been seeing, and different gun sales sights the statement,” this Winchester has matching numbers”.   I understand that if you are talking about a model 12  where the receiver and the barrel should have matching numbers but I am seeing it on Rifles, most recently on a model 55 Winchester.  Can somebody tell me where there would be numbers that should match up on a Winchester 55 or any other Winchester rifle.  I ask one of the sellers what he was talking about but never got a answer.

I see this from time to time on old cars and most people do not understand the meaning.  There are no parts such as a engine, transmission etc. that match.  The matching numbers on a car means the parts match what was on the factory build sheet .  Without the build sheet you would never know if you have a car with matching numbers.  

I have a numbers matching and date code correct car.  I will explain one part.  My engine block has a cast date and a cast part number.  The block is stamped the exact day that it was assembled and was given and stamped a sequence number.  The Vin includes the scheduled build date of the car.  All the parts on the engine have part numbers and cast dates.  The engine block was cast in December of 63.  The engine was assembled a couple weeks later still in 63.  The car was built in the first week of January 64. All of my date codes parts were made between September of 63 to December of 63.  Some parts are marked with the exact shift the part was made.

Guns aren’t marked like this but you have to know what parts were made when.  You don’t want an old gun to have newer style parts.  The reverse is OK since old parts were not thrown out.  They were used up till they were gone.  Some guns have the receiver and the barrel marked with the serial number.  Special Winchesters had assembly numbers put on the parts so they stayed with the correct gun.

  On Dlx grade 73s and 76s the side plates have the last two digits of the serial number stamped inside. I suppose they were fit before the finish was applied and needed to be assembled to the same frame to fit. It is not uncommon to find a side plate a few digits off, but original to the gun, I can only speculate the side plate failed to fit or match after case coloring and another was substituted. T/R

TR said
  On Dlx grade 73s and 76s the side plates have the last two digits of the serial number stamped inside. I suppose they were fit before the finish was applied and needed to be assembled to the same frame to fit. It is not uncommon to find a side plate a few digits off, but original to the gun, I can only speculate the side plate failed to fit or match after case coloring and another was substituted. T/R  

That’s interesting Tom.  I don’t like messing with side plates but I guess I might have to now.  One of my deluxe guns has an assembly number off by 2 digits on one of the parts.