Wonderful grouping of six blocks of four 4¢ Project Mercury postage stamps, each signed in ink by a Project Gemini astronaut (with two signing multiple times). Includes: Frank Borman (signed four times), Thomas Stafford (signed four times), James McDivitt (signed once), Charles Conrad (signed once), Elliot See (signed once), and James Lovell (signed once). In very fine condition, with poor-to-moderate signature contrast.
