I acquired recently a keywind lever set 18s watch and after taking it apart to clean it, found that it was actually a model 3 with 5 pinions. I checked the serial numbers of the mainspring plate and it matched the serial number of the rest of the watch. Has anyone else run across one like this?? The movement is in pristine condition as does are all the parts. I don't think anyone changed it because all looks so new. I'm wondering if it was a special order or something. What do you think??

Any photos William....we like to look....

Regards,

Jerry

even the serial number . . .

"Fifth pinion" Ilinois watches were transitional movements with both a square winding arbor on the Mainspring Barrel cover, and the Pendant winding apparatus. The 5th Pinion was added to allow the second hand to work in an "open face" situation.

The picture below shows the fifth pinion between the Hairspring Bridge and the regulator arm.

You have a very nice piece of history.