French Guiana 1920 Cover with CL5 Tied by Avion Large Box Cancel

French Guiana 1920 (Jul 12) Cover with CL5, 75c T.A.G. semi-official airmail with La Société des Transport Aériens Guyanais domestic use, prepaying the internal airmail fee from Saint Laurent du Maroni to Cayenne. Only 500 of this stamp issued on July 8. Stamp is VF with four margins, completely sound unlike most examples we have found. Nicely tied by less common sans-serif Avion large box cancel. Slight cover flaws in UL as seen in photo. Cover lightly folded not affecting stamps or postmarks. cv $1750.