I thought your estimate was pretty close based on the pics presented. (hopefully that is the extent of the rust). A 67 in general will pull slightly more than a 68 (like for like). But with non original drive train, non-SS, automatic car, there isn't a lot IMO that is going to drive the price/value way up. I do like the color combo, and the RS package looks great for 67 an 68 Camaros.