I ran across this item (minus the electric winch) at an antique store on the square in Paola, KS, last Saturday. Second floor rear.
It is an olive green pressed steel crank. About 14" or so. Aluminum handle with three 1/2" female cut-outs that give more or less leverage/radius on the turn. I suppose it is a back-up in case the electrical system goes out.
Marked 35B3441 They were asking $7.
http://www.worthpoint.com/worthopedia/lancaster-bomber-b17-flying-fortress-481946972