cover 1851 (22 Mar.) entire letter written at the Palace, Valletta to London, rated "1/3" in red ink, showing a barely legible strike of the black "MALTA/PAID" double-arc d.s. (MPC-1b) with clear London Paid arrival c.d.s. in red and, on reverse, good Malta double-arc d.s. (MLC-1c). An unusual combination of markings