CMMG is just finishing a run of pencil barrels in 1/12 and 1/7 for those that want the handling of the SP1 wihtout the cost of an original. They are doing a 16" and a 20". I have a 16" 1/12 and the thing is weighs nothing. There was also some talk of someone doing a run of A1 uppers, not the C7 style uppers like Bushmaster sells.

In the retro forum on arfcom, there is a dealer selling new A1 lowers.