Donnie Brown, have you added headlight buckets to the early/late 1926 differences? Tom Carnegie was kind enough to point out some different water drain hole locations on left to right buckets. Someone mentioned that they did not have any drain holes, perhaps earlier ones, and others mentioned they had two drain holes in a given headlight bucket such that it could be used on either side and still have a drain hole on the bottom. I could only get one of mine apart at this time and it has two drain holes, so I guess it could be for either side. Another thing, there is apparently a flat and round type of headlight bucket near the center where the bulb mounts. Donnie, have you done a study on the headlights? Unfortunately the water drain hole will be hard to seen unless one disassembles the headlight rim from the headlight bucket!
The tie bar is another early/later feature along with the later mounting of the headlight bucket on the crossbar!
Donnie, if this keeps up your book on 26/27 differences may be the size of McCalleys' "The car that changed the world". Better hurry and write if before the postage to mail your book will cost more than the book!