I have not heard of Red Cat, but there were several sources for after market heaters. Arvin was a popular brand, as was Hadees. Of course Western Auto, Sears, Montgomery Ward, Firestone and many others had their own private label brands. These were manufactured for them by the same companies who were selling heaters under their own names. Harrison was the GM division which produced radiators and heaters. GM sold aftermarket generic heaters branded as Harrison also.
Mike
