I checked the Springfield database that I've been maintaining and believe that this rifle has its original barrel. S/N 11467 and S/N 12005 both have 1-42 dated barrels and bracket this rifle's S/N. I don't see an open-box SA cartouche on the stock. It's nothing special in my judgment and does have that funky-numbered bolt as Herschel pointed-out.
By the way, the highest S/N M2 I've ever observed was auctioned this May 2nd by Cowan's. It's S/N 21129 and went for $2,530.00 including b.p. Go to:
http://www.cowanauctions.com/auction...?ItemId=110424 It would be almost impossible to improve on that one, from what I can see - and it might just be the last one. I called Cowan's and the barrel date is 7-42.
Next highest in my database is S/N 21089 owned by a forum member. I own S/N 20205. All of the S/N's given are "Issue" rifles.
Joe