Brad...
Those are NOT coaster cars. Those are NAD railroad cars. Apparently, NAD offered two styles of rail cars...the ones with the roofs and benches as used at Americana and Camden Park; and the "streamliner" style found at Erieview Park. Lakemont Park also has one of those NAD trains.
The cars are 4-bench cars that look an awful lot like the 3-bench Century Flyer cars, except that there is no lap bar mechanism and if I remember correctly, the seats are not upholstered.
Erieview Park does have a coaster, "The Brat", which is either a Molina or a Schiff. I'm not sure which, as Molina coasters are in fact Schiff coasters sold after Schiff went out of business.
--Dave Althoff, Jr.