When it came to Halloween costumes, the two biggest names in the 70's were Ben Cooper and Collegeville. If one didn't have a specific license, the other surely did.
In the mid seventies, Ben Cooper had a lock on some prosperous licenses namely The Universal Monsters and Superheroes from DC and Marvel houses.
This left Collegeville with some interesting choices and a great deal of "imitation brand" characters. Concentrating on cartoon characters and popular toy brands, Collegeville has a real mix of fun knock off costumes that would be fun to collect.
While looking through this catalog, I was shocked to discover just how many halloweens were done by collegeville in my lifetime. It must have had a lot to do with my proximity to a Woolco.:
And Remember, each Collegeville costume is Flame Retarded, so you know it's good.