If it is a part needed to restore a sporterized rifle to original configuration, it probably isn't available anymore through the major parts outlets. If it's a normal part to replace something broken or worn, they seem to be available. A lot of guys trying to bring rifles back.

Patience is required for ebay but the end result is generally satisfying. If you're looking to do things quick, you aren't going to have much luck at that. Every time I get something new I want to get it restored as quick as possible. In general, within 2 months I will have accomplished that. Exceptions have been cleaning rods and bayonets that are expensive as all get out. Cleaning rods are one of the most common missing parts on the old stuff and bayonets have specific collectors that don't collect the rifles.