This carded set was also sold by LP under their own trademark (see set #204), and can contain different colour versions of the Explorer Car at lower right. Because an Explorer Car is included and no mini-Matt Mason toys, I believe this is a very early set dating from at least before 1967 (when Major Matt Mason was first introduced by Mattel). Somewhat obscured by the flash, the grey figures at top-centre are the aliens as also illustrated on the card.