How long has top of the gasoline pump advertising been in wide use?

Factual Questions
1

They are called Pump Toppers®, though I don’t if it is like Kleenex® where they are the name of the industry but not the only producers. I’ve looked up the trademark, which gives me a date for the trademark; but it doesn’t tell me if they were in wide use before 1994.

Were they around before that? How can I find out? I’ve had no luck hunting down Pump Topper Inc. or the guy who first applied for the trademark.

Thanks much.

2

I don’t think the now-standard flat topped gas pump existed at all prior to the 1970s, and I recall the early ones as being somehwat taller (hence, less easy to see anything on top of the pump).

Since the Pump Topper had to follow the development of the pump style, maybe you could find “gas pumps through the years” and narrow it down like that.