1943 FDC / Reg and airmail letter with return sheetlet to England, franked with 3 str-of-3 from bklt issue of airmail stamps 6c, Sc.C25a with machine cancel. WASHINGTON D.C. Mar/18 1943, on reverse supplemented with stamp 1c, arrival postmark DR ČESKOSLOVENSKÁ POLNÍ POŠTA 26.Apr. 1943, censorship marks; light fold