Here is a photo of an early Model T generator brushplate used from October 1918 to approximately November 18, 1921 when is was designated "obsolete".
I have only seen three of these in all the years I have been rebuilding generators.
Notice there is only one slot for the unique third brush holder to move in the plate and the adjusting nut is on the sliding stud below the spring. The spring is also unique part number T-1988 designed to fit the 3/16 wide slot on the top of the stud. Details about these and later brush springs may be found in Vintage Ford Magazine Vol. 40 Issue 5 page 24.
The reproduction brushplate insulators available today will not fit this early brushplate.
A later brushplate may be installed in the early generator cap.
Ron the Coilman
11/18/21
RON excellant about 2-3 months back i just put one away with a handful of other brushplates thinking at the time it was odd and unlike the others i didn't think it was for a T now i'm glad i saved it. RAY
Just looked in my stock of brush holders and found 12 NOS early holders and bolts. Have one extra with the Fac. number T1821 in it. Probably have the rest of the holder around. Was the Liberty name on the early units a brand name that Alison used?
Fred Allison worked in the electrical engineering department at Ford. Liberty Company manufactured the first starters and generators. Every now and then you will find a unit with a red oval Liberty tag.
The system was called "FA Liberty Starting and Lighting System.
Ron the Coilman