[leddzepp]

Nos parts are held onto and sold as prices go up. A lot of them aren't purchased for actual use, rather they are looked at as investments...and it's easy to see why with watching how a lot of them bring big $$$. GM no longer makes them so the price has nowhere to go but up.

Used original parts stay in place. Replacing them with NOS pieces doesn't make sense when everything else surrounding it is worn, unless you are doing a full blown restoration.