Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - United States - Air Post stamps - 1978, Wright Brothers, 31c+31c multi, block of four vertical se-tenant pairs and extra pair of No.C92, six stamps in the middle with black instead of blue inscription (US Airmail 31c) at bottom, full OG with minor disturbance on top pair, NH, VF and rare, Est. $500-$600, Scott #C92a, var