Welcome to Super Galactic Dreadnought! I've been a science fiction fan since before the first Star Wars movie came out (back then, of course, it was just Star Wars--we had no idea there would be sequels!) and a wargamer since my teens.
There was the source of the picture I had seen in the magazine: starships of the Terran Federation, along with additional pictures depicting the other four powers in this game (Aquarians, Avarians, Entomalians, and Carnivorans) in what the manufacture said was 1:1200 to 1:9600 scale! Not only that; there were lists of every ship class for every species, with evocative designations such as Starfighter, Starbomber, Stellar Cruiser, Galactic Transport, Galactic Attack Carrier, and Super Galactic Dreadnought.
Not only that; the sheet also offered "Galactic Armor Models" in 1:285 scale. They had MAATAC Corps for each of the five powers as well (MAATAC = "Multifunctional Armor and Armoured Tactical Attack Commputer"), with light, medium, and heavy Galactic War Machines. There was even a set of rules (the eponymous MAATAC).
Unfortunately, as a youngster, I never had the cash flow to purchase any of these product via mail order. Still the imagery and the concepts struck a chord with me, and I hung onto those catalog pages for years, before they disappeared in the mists of time. It would be decades before I reclaimed that lost part of my youth.