Only available through a crowdfunding project on Zoop, 113 have been claimed during the funding period (singular and bundled).
Official marketing text:
To help celebrate The Rocketeer's 40th Anniversary and first museum exhibit (showing at the Comic-Con Museum in San Diego from March 9th through July 31st), please join the estate of Dave Stevens, creator of The Rocketeer, in honoring his legacy by supporting this project.
Zoop is proud to team up with The Rocketeer Trust to present THE FIRST ROCKETEER PUZZLE EVER OFFERED IN THE U.S.!
