Watermark Check: You will need to check the watermark on this stamp.
|Number||Watermark||Privately Perforated by the Following Companies/Types|
|343||Double-line||Attleboro I; Brinkerhoff I, II, IIa,IIb; Mailometer I, Ia, II, III, IV
Farwell 4a4, 4B4; Schermack I (8 holes), II, III; USAV Ia, Ib, II, III
|383||Single-line||Brinkerhoff I, II, IIa, IIb; Farwell 2B3, 3A2, 3B2, 3B4, 4B3, 4A4, 4B4, 4A5
Mailometer I, Ia, II, IV, V; Schermack II, III; USAV Ia, Ib, II, III
Note that these stamps are seldom faked, rather they are the starting point for many of the more dangerous forgeries in U.S. philately. The primary reason the imperforate stamps were issued was to supply stamps to the vending machine manufacturers who in turn applied their own perforations in order that the stamps would feed properly in their machines. Imperforate stamps were also supplied to collectors upon request and these are the stock from which many of the flat plate coil fakes were made.