10c dull violet 'Momotombo' postal stationery envelope (H&G B41) used with added 1900 15c blue 'Momotombo' issue (SG 144) tied by oval BLUEFIELDS cancel with fine handstruck 'BLUEFIELDS NIC' registration marking alongside. Addressed to GERMANY with NEW YORK EXCHANGE registration label applied in transit plus various other transit and arrival marks on reverse. Very fine.