The Droid Factory Playset came out in 1978 in a Star Wars box. It was also released later in a ESB box. The ESB box version is much harder to find.
For the most part all things are similar, although there a distinct variation in the base color can be found.
From researh it appears the Dark Brown base came to late in the ESB box, making the brown base much harder to find. The lighter color base has been found in both SW and ESB boxes.
Of course the coolest part of the Droid factory set is the 3 lever R2-D2. with its funky 3rd plug in leg.