Well, you have to remember that your slide is from the pre television era, in that sort of rural location. So the graphic advertising channels were limited to the local newspaper, and the cinema/drive in!
I once owned one of these slide projectors. Dunno just how old it was, but it was salvaged from a closed cinema in Tocumwal, NSW in the '70s. The slides I picked up along with it were early '60s vintage - I recall one of them was for the FB Holden car. No mower slides though. Ended up donating the lot to a museum in the area.
