There are a handful of items that are reproduced that are authorized by GM. Most everything else is reproduced for first Gen Camaros is made in China. Year One, OPG, there are numerous suppliers, some parts are reproduced by different companies with varying degrees of quality. If a Camaro owner wants a sure fit or top shelf part, he/she will look for an original or New old stock GM part. There are actually quite a bit of NOS parts still available from private sellers, who have stock pilled parts over the years. A parts car will turn up from time to time, and is a good source for original parts. Most of the time reproduction is frowned upon because you have a good chance of it not fitting, or looking correct. The NOS or original is as good as it gets, but not all reproduction parts bad. Trim parts makes nice emblems for Camaros as well as many other makes and models, I have never received a bad emblem from them, and I would rate them as one of the better reproduction companies out there. I believe that all of there items are GM licensed, I am unsure if they are using the original tooling or not, but they make a nice product. There are also other guys out there like Jerry MacNeish who certifies Camaros, and he also sells a limited amount of parts, or rebuilt items like alternators, distributors, and smog systems. His smog systems for instance use some reproduction parts, but visually I am told are spot on.
I hope this helps you out in getting an understanding of the parts situation for first Gen Camaros.