I have searched in most common spots for the build sheet on my 69ss. I am the fifth owner and a fairly involved restoration was done in the past. However, the Chevelle has been owned its entire life within a fourty mile radius. Although I've never met the original owner, a previous owner of my car has. The original owner lives in just the next county and always has. If I was able to find the original dealer, what type of info specific to my car would I be able to obtain?

It's hard to say. The original dealer may still be around, or they could have gone out of business years ago. Even if they are still in business, many dealers do not keep records that far back. But if you can get in touch with the original owner and find out where the original dealer was/is, I would definitely try!