I saw one on E-Bay about 6-8 months ago and have been intrigued since they were originally in operation.
A TF was used for the body molds, and it was a proprietary frame to which all the running gear from a B was installed, thus keeping it all MG. It was lighter, faster, and stronger than the TF, just not original and less expensive.
I believe it started out as the Great Lakes Motor Car Company, but at some point it went to the Victo TF 1800. Someone on E-Bay is selling one of the original sales brochures.