GB Postcard 1906 King Edward 7th 1/2d Used in Zanzibar

Pre-Paid Post Card from the Parliamentry Election in London for support of Sir Philip Magnus, returned by J. Hine, Mkunazine, Zanzibar, bearing Great Britain SG217, 1/2d yellow green tied by Zanzibar squared circle, invalid with circular handstamp and charged 1 1/2d on arrival in London, delated with manuscript PAID. Unusual item. (pt)    ID: 29415