A Plague of Perruques:
From the Title Page: This short adventure originally appeared as a tournament for convention play for Traveller, the science fiction role-playing game set in the far future. Although planned for publication, it never appeared as Double Adventure 7.
From the description: This adventure is a Traveller tournament for anv number of teams. each team consisting of eight characters. It is a single session scored adventure, which means that the team of players which best handles the situation (as scored by the referee) is the winner. The adventurers have been recruited by Ganidiirsi hault-Reitan (one of the player characters) as part of an informal team visiting worlds in the subsector. The Baron Reitan's purpose is two-fold: he has been visiting his own holdings on various worlds between Regina and Efate, and he is helping in the recovery by managing problems that come up.
Stranded on Arden:
From the title page: This short adventure originally appeared in Adventure Gaming magazine No. 6, December 1981. A variant (set on a different world, with a different date, and some details changed) was included in The Traveller Book. Although planned for publication, it never appeared [in print] as Double Adventure 7.
From the description on Page 4: This short adventure, entitled Stranded On Arden, is a complete adventure for Traveller. It concerns the exploits of the crew of the far trader Empress Marava on the planet Arden.