I just did received a FOIA request for the weapon from the U.S. Govt to see if they head any records on the weapon to which the carbine had a short list of results:
The following Information was found in the DoD Small Arms/Light Weapons Registry for a M1 Carbine, .30mm Caliber Rifle, NSN: 1005-00-670-7672, Serial Number 5155157. The records for this weapon are listed below in chronological order:
1. 11 August 2008 - HQ Army Tank, Automotive and Armaments Command (TACOM), Anniston, Alabama received the rifle.
2. 15 December 2008 - HQ Army Tank, Automotive and Armaments Command (TACOM), Anniston, Alabama shipped the rifle outside the Department of Defense (DoD).
Interesting, considering on other rifles I have FOIAed, the serials usually have a date of entry into the system and arsenal or holding area they were at when they were entered. This example lacks that as well as what military unit shipped the carbine to TACOM before the 11th of August 2008. The Disposition does show it leaving the DoD, but I have seen in the past (though a sample size of three personally) that it usually lists who it was shipped too when going out of the DoD.
I have also tried conducting queries on the CMP auction sight using their past auction search tool. The earliest auction for M1A1s I have found were in 2014. If it was ever auctioned there which I would imagine it would be because of weapon still being in Govt. possession as late as 2008 then a search did not reveal those records.