I used to work for the much derided century international arms/ century arms international. And while I didn't work there in the 80's (mid 2000's)
So hopefully I can give ya some history regarding them here in the US. But ill try to only cover the "L1A1 type" rifles.
But I began my gun studying and learning at that time. Throughout most of the 80 and early 90's all saw in the US for FN FAL type rifles were British L1A1's built on mostly metric (IMBEL and FMAP Argentine recievers, and some had Imbel but modified to accept INCH magazines!!)
Most I saw had the black Marynol (spelling?)Furniture though some had wood both British and Austrailian and most had black stoving on them but some were blued. Some later ones had crummy thumb hole stock on them for import purposes and had the flash hiders cut off and the barrels recrowned.
For the most part these early guns while mix masters (jokingly called MINCH for Metric and INCH) but where pretty solid rifles. Specifically because century didn't make or subcontract the receivers to US companies. Most of these guns used metric magazines but I saw some that used INCH. With the Inch cut guns you could sometimes use Metric mags in them also but they were wobbly.
Century eventually they started building guns with US receivers but the quality was really hit or miss, some decent and some totally don't function and or cannot reliably. Here is a decent thread of some of those makers
http://www.militaryfirearm.com/Forum...nd-information
As for other common wealth rifles. I have hardly never seen any Canadian C1 or C2 rifles. they are very rare in any form here in the U.S. hardly ever as parts kits. Which makes me think the Canuks have probably hung onto them in storage. I have seen some Aussie rifles, but far more as parts kits later on say in the early 2000's. Also I have seen some L2A1 LMGs built as semi auto rifles. And a few parts kits. I did aquire some of the 30 round canadian magazines which are excellent unlike the 30 round L4A1 magazines from the 7.62 NATO BREN these are unreliable in the L1A1 but look super "Ally" as you blokes put it.
Keep in mind these where all Semi-auto only rifles unless converted to full auto before 1986 by licensed manufacturers of machine guns. That being said I have seen several that had been converted to select fire by back woods bubba gun hack types.
Eventually century couldn't easily get L1A1's anymore and started importing G1, R1A1,STG-58, but that really wasn't until the midish to latish 90's. They made a very small run of L1A1's when I was there in 2006 and I think it was the last of the inch parts. Though they where still making various Metric rifles till 2010 or so.
Hopefully that was useful to someone
Brother in Arms