(Cameo) Mayer & Macdonald, Gas Fitters & Manufacturers of Mayers Self Regulating Gas Nipple. Green illustrated cameo corner card showing Gas Heater & Lamp Fixtures, on fresh cover to Boston, Mass., franked with four margin 1851, 3¢ dull red tied by blue "Baltimore, Md., Nov 2" cds, Extremely Fine, a wonderfully choice illustrated cameo in green. Scott No. 11A  Estimate $250 - 350. $0 (Image)