Despite being cheap plastic toys, Spacex and Golden Astronauts got about as much advertising to the consumer as more expensive toys would. What we've found so far is shown below.
In the US, it were primarily budget department stores as well as the mail order companies that included Golden Astronauts in their catalogues. In the UK, advertising was more extensive, with the Spacex range receiving fairly regular advertising support in boys' comics papers. And I do believe there's at least one campaign (the 1969 launch ads) we haven't found yet.
Click on images to see each item