Looks like Rick beat me to the punch. The Springfield Research Service was founded by the late Frank Mallory. After his passing it has changed hands a couple of times and is now being run by one of his former associates as an affiliate service of the U.S. Martial Arms Collector newsletter. Basically the SRS provides a research service for government records from Springfield Armory and other military sources, which are mostly now housed at the National Archives in Washington. Opinions vary about the quality of service these days, but an SRS letter and documentation for an NRA Sporter would almost certainly add value to a serious collector.

Basically if you subscribe to the Collector quarterly newsletter ($35/yr) you can send them an inquiry by email, and they will let you know if they have any archive information available for your weapon. If so, for an additional fee ($150 if I recall correctly) they will provide you with a letter of authenticity and copies of any records that they can find. Sometimes the records are quite extensive (e.g. specifications, build notes, name and address of original owner, correspondence, etc) while other times they are quite cursory (e.g. a single entry in an arsenal rebuild registry).

The SRS used to publish books of serial numbers (very sporadically) and also offered a CD that was a compilation of the books and all updates published to date. At one point they even had the records online, but that was taken down long ago and it has been at least 10 years since any new publications.

Links http://springfieldresearchservice.com and http://usmartialarmscollector.com

Link to one discussion about the SRS (there are many on the Web) http://www.jouster.com/forums/showth...search-Service