These scans come from my brother Scott. He still has some of the old Star Wars catalogs that came with the toys and some some of the instructions. The Droid Factory came out in 1979 with a Star Wars box and was re-released in 1980 with an Empire Strikes Back box. It came with blueprints to build several different droids including a three-legged R2-D2. Also included was an order form in case any of the many pieces were missing or broken. You can read more about it here.