I think this might be for a Fordson. I tried holding it up to and older and earlier T engine an can't see how it fits as is.
It is a gear drive for a dual ignition, which suggests two spark plugs per cylinder, or perhaps two Model T engines mated together in one of the WWI tanks? Just guesses, but the plate is obviously made to accept two Ford Model T timers.
Guess I'm not looking at this the same. I don't see how this can be dual ignition. where would the other timer go? am I missing something? My guess is a adapter to run a later generator on a early pre 1919 eng. just a guess.