SIERRA LEONE 1991 SWISS CONFEDERATION ANNIVERSARY UNADOPTED DESIGN
150l Swiss Confederation Anniversary unadopted imperforate proof single prepared for the Anniversaries & Events issue of 20 December 1991. Affixed to thin card ex Questa presentation folder. Very scarce.
Note: similar designs were released 23 December 1991 for Guyana and 29 January 1992 for Maldives
