I'm pretty sure they have a milk paint finish, like the chairs in my breakfast nook. They were made by Sayboldt Cleland in Pennsylvania, probably during the 70's, but my research did not turn up the paint finish they use. I'm goin' on assumption. The finish looks just like the milk paint on my Dimes chairs in our breakfast nook. The new-old chairs are solid and sturdy and I'll be using them in my office at work, although I'm kind of liking them in my home for "extra seating". I'm planning on touching up the scratches---I really want to paint the entire chair, but we'll see how the touching up thing goes.
Milk paint has been around for years and years in some form--say thousands. There is apparently one company [The Old Fashioned Milk Paint Company in Massachussetts] that makes the original powdered formula. You add some water to the desired consistency and voila, you have paint. You can also add white--or other colors--to modify the standard shades for an infinite variety of custom shades. Plus, it's environmentally friendly....they even have it for walls now! I'll be posting the process so you can see how it goes. Can't wait! I'm going in painting mode.