The stamp inscription gives “schooner” but she is a topsail schooner, sometimes called a square topsail schooner.
The after mast is mostly longer than the foremast. The rig type dates from the 18th century, although the name not adopted until the mid-18th century.
This type of vessel has two masts, each made of two spars. The mainmast is rigged exactly like the mainmast of any other schooner (i.e., fore and aft mainsail and gaff rigged topsail) but the foremast, though having the typical schooner's fore and aft rigged mainsail, has above it one or more square rigged topsails. The arrangement requires the ship to have a foremast yard (the lowest) from which no sail hangs. The foremast and all of its sails are comparable to that of a brigantine (see below). If there are square rigged topsails on both masts, then it is called a two topsail schooner or double topsail schooner
Somalia Republic 1998 400 SH. SO. Sg?, scott?
Guinea 2002 750f sg?, scott 2064.
British Virgin Islands 60c sg 206, scott?
Newfoundland 1965 13c sg 29, scott 30
https://en.wikipedia.org/wiki/Sail_plan Aak to Zumbra a dictionary of the World’s Watercraft.