As was said, it is probably a Century built gun. Find out if it is an "inch" pattern or "metric" pattern rifle. If, on the side of the upper receiver you see the word "Imbel" it is a quality built receiver of the "metric" variety. These were the best ones Century used.
Go to TAPCO and order an FSE hammer/trigger/sear kit. It runs about $49 but it is head and shoulders above the Century made pos's. DSA also sells a similar kit for around $100 but it's not twice as good as the FSE parts, it's about the same. These are 3 US made parts.
Order a US made stock/handguard/pistol grip kit. There are many to choose from. Here are 3 more US made parts.
You can add a US made charging handle and or gas piston for a total of 8 US made parts. But you need only 6 if you have a nekkid muzzle or 7 if you have a muzzle brake.
For example; Add the FSE h/t/s, a US made pistol grip (the TAPCO SAW grip is the shiznitz, I love it), a US made buttstock, a gas piston and you have the 6 pieces you need, if you want to retain the current handguards. (maybe you like them and want to keep them. You can. Just switch out other parts)
Visit the
FalFiles.com. These guys know their FAL's and will be more then willing to help you out.