In the late 70s and early 80s, “Original” brand scopes were sold by the U.K. importers of M&G Diana “Original” brand rifles. They were made in Japan and like all Japanese scopes then they came with the little round yellow sticker that you describe.
Early 80s Japanese glass is often quite nice, sometimes very good. I’d say the “Original” brand ones are in the middle of the pack. Comparable to contemporary ASI, Kassnar, Nikko-Sterling, Hunter and various others.
It probably cost £20-25 back then, equivalent to £70-80 now.
Worth about £15-25 now, depending on condition.