back in the day, amusement parks not only owned their own rides and attractions but also had leased spaces where an independent operator could bring his own ride, foodstand, game, or what have you and operate it for a fee. before the policy of pay one price, tickets were collected and I believe that vendor was paid the money then paid the park for his space. Cedar Point was no exception- throughout the 1940's and 50's especially, many rides and food stands were run by independents. this is why rides might appear for a season or two then disappear to be replaced by something else. as Cedar Point became a large corporation they made effort to take over all operations as their own, particularly in the ride category. when i worked at CP in the 70's i was in food service but actually worked for Interstate United, a contracted food service. another good example that comes to mind is Berardi's french fries- they were a Sandusky family that operated a restaurant in town as well as their seasonal operation at the Point. eventually all ride and food operations became CP's own. (it was a surprise to me that a restaurant like Johnny Rockets opened at the Point-seeming to reverse the trend- especially when CP operates Coasters, a "similar" venue just up the midway). can we hope for a Mrs. Knotts fried chicken?
as for the Rotor, it was a ride that was brought to the US by a man named Hoffmeister in the 50's and those huge wooden stuctures appeared just about everywhere. the name Rotor was considered generic and various styles and models of a similar ride popped up, particularly in Europe. when Chance developed their new style Rotor that we know today, they had a patent or trademark or copyright (or whatever) on the name. as the old Rotors were removed due to age, any new ones manufactured in that old style were renamed Hellhole, ( I remember seeing ads for it) and Chance manufactured their version under the name Rotor. my guess is that CP removed their original Rotor due it's old-fashioned nature and jumped at the "Chance", so to speak, when a sleek version of their old ride was developed. you could find Hellholes not only at Conneaut, but at Fantasy Island and i remember a particularly wicked version of it at Coney Island in new york.
i recall some of this information from an article i read many years ago in Amusement Business entitled "Rotor, Rotor,...Who's Got the Real Rotor." i had forgotten all about it until i read Mr. McKinley's "trivial" question!