I got one of these R1A1's a while back. Mine came just like yours, SS# tag on trigger guard, two newspaper wrapped mags. Nothing more nothing less. It has the Century receiver and Black US furniture. (no place to attach sling) I have the parkerised version and finish is pretty good. I added a pin to the mag release so that the bolt stays open on last round. UK did not like the open bolt, due to dirt entry and that is where most of the receiver parts come from. (or AUS) I have taken my apart many times, every thing was very dirty. My mags was VERY tight too did not take file to them, just wore it in after a couple of times to the range. Cool gas system, it's adjustable based on the bolt cycling enough to feed next round. Shoots nice, wish I had the bipod. I am sure it would be tough to control in full auto. Looks mean, makes a big hole, and came in a color that looks good on me.(Black) But AR's are still my fav.
I paid $389.00 with two mags, plus $10 shipping and $10.00 to my FLL.