David, if you have not already done so, I'd suggest that you read Bradley (Brad) S. Klein's book, Discovering Donald Ross. It will give you a great start, and frankly there's not much else, in learning about Ross design and construction. Wonderful book.
My club's Donald Ross course dates from 1929. Until five years ago it had not been significantly touched (except for tree plantings). The greens were (had become?) small and round. Our restoration/renovation architect, Kris Spence, could point out the old green perimeters, which which were "squarish" with now-off-the-green-edge high points, small knolls, indicating the start of ridges that would have come into the greens. Although Kris had no detailed green drawings to go by, I believe that Kris did an excellent job of bringing back the old green shapes and contours, where they could be discerned from the surrounding areas. Based on my reading of Klein, and other fuzzy stuff (that's my fuzzy mind, not the original stuff) I picked up along the way, I think they'd be best described as Walter Hatch-style greens.