Could this movement have been manufactured by jaeger lecoultre? This is in a watch sold by JW Benson of London who used swiss movements after World War 1. Diameter is 21.5mm and pin set adjust. Mainspring winding is unusual and similiar to other jaeger lecoultre examples. Ideas please.
Looks like a "generic" Swiss movement to me. Yes some of the bridge construction looks like some JLC movements, but I think that's where the similarities end, but anything is possible.