The tools in the 1906 through 1909 parts books don't show a logo, although the Ford logo on the radiators of the 1906-08 Models N, R & S, all had a script that was supposed to imitate Henry's actual signature. Known as the "winged" script, it continued until sometime in 1910.
The block letters used on the hubcaps of the early cars also remained until sometime in 1910.The 1911 cars had the script minus the 'wings'. Here is a 1909 hubcap- If you would like an enlargement click on the thumbnail...