PANAMA 1958 BRUSSELS EXHIBITION AIRPOST Sanabria 233a IMPERF PAIR UNISSUED DSGN.

1958. Brussels International Exhibition. Scott & Yvert unlisted. Sanabria 233a. Marginal imperf pair. UNISSUED DESIGN, small B/1.00 at top right. PARTIAL DOUBLE IMPRESSION of the CENTER. Mint never hinged. Some tropicalization otherwise VERY FINE. Scarce.