UPDATE (from the comments, Thanks Viv): A link to the inner workings on the Twingles
This one is for my buddy Doug who has a real thing for these oddly engineered bikes. I actually know the brother of the gentlemen who restored this bike and from what I heard it was a remarkable effort to get it this nice.
I found some more on this engine here http://home.sprynet.com/~inniss/sears.htm