21" vintage bike, perhaps Jack Sibbitt

A lovely vintage machine looking for a new home.  It's been suggested that the headtube and fork crown lugs stronglt suggest it's made by Jack Sibbitt. 
21" seat tube CTT, 22 1/2" top tube CTC, 120mm head tube, clip style headset, Brooks Professional Narrow saddle, Williams chainset, (AU code dates that to 1955), modern Weinmann brake levers and callipers.
A lovely machine that deserves a good home to go to - recently serviced. 
Collection from Banbury preferred, but happy to send by courier.