A quick Internet search returns hundreds of dealers with searchable databases of classic car parts. Type in your make/model/year and a description of the part you're looking for, and you can have it express shipped to you in a few short days. More often than not, it'll arrive looking shiny and new, ready to be installed.
On the downside, this can also be the most expensive way to find parts. If you're long on cash and short on time (and experience), this is a great way to go. If you've been playing the restoration game for a while and don't have deep pockets, keep looking.