I recently purchased a M1 Garand without knowing the history or condition of the rifle. I was told by the previous owner that it was not a numbers matching firearm. I decided to do some research and found that the only serial number on an M1 is the receiver and that the other numbers are batch numbers. I also found that the date range of the a batch number does not always have to match up to the date of the serial number in order to be correct.
For the "run of the mill" surplus firearms like the ones you would get from the CMP for a good-fair price how important is is to people to have a "numbers matching" firearm. I have noticed that U.S. surplus firearms are really not numbers matching in the same way say an old German or Russian firearms are with the serial numbers stamped on multiple parts of the firearm.