The pebble grain handguards look original to me and not USA made. The carry handle doesn't count towards the part count. The stocks you have now are inch style. I don't know about the buttstock or handguards, but the pistol grip is different between inch and metric. Try the sites Pookie gave you for replacement stocks. To remove the front handguards, just remove the screw that connects them at the front.
I saw a set of forends that look just like mine not sure where now for sale and it said US made by Century.
If this isnt US made I can find them US made for 14-20 bucks and I found an inch stock and pistol grip from DSA for $94.00 and from another place. I cant remember it off hand but it was a US made stock and pistol grip for $69.00.
Im still working and looking and learning.........
I got an email from CAI here is what it says.
The parts that we install in our firearms vary from make and model , and are considered proprietary information. We comply with all federal firearms regulations and ensure that all of our firearms are in compliance with Title 18 Chapter 44 para 922 (r), Para 925 (d)(3) and 27 CFR para 479.39 (c). We take special care to ensure that no more than 10 foreign parts listed in para 478.39(c) are installed in any firearm that we make from imported parts.
There are some under a misconception regarding the number of US parts required in a specific rifle. It is not the quantity of US parts that is restricted, but the number of imported parts that is restricted as outlined in par 478.39 (a) & (c).
Century does not divulge the parts lists, as we know the guns leave our factory in total compliance. Also, it is not possible to be exact, because it is the number of parts, not the specific parts themselves...so that is not kept noted for the hundreds of thousands of rifles we sell.
From my experience, the parts that are US have been receivers, triggers, hammers, pistol grips, stocks, sears...etc. But AGAIN, that does not mean we use the same formula for every rifle. Most US parts are signified with a "C".
Also… A US replacement part is not always marked, but should be bright finished and is threaded into the carrier. It is secured with a small weld where the holes for the cross pin would be set. The original part is secured with a cross pin through the threads to attach it to the carrier and will have a blued finish on the face of the head. Examination of the part should show the origin. If it is original, it can be easily replaced.
I found a CAI stock set for the L1A1 that should be here this week. I did a trade for it and I cant wait to get it on the rifle and see how it looks and feels in its original form.
I got the stock in and now just have to take off the old one. Im a bit nervous to do this lol but will dive in just like I did my AR.