Ansley Fox was certainly a "marketeer". However, since there does not appear to have been a registered "Sterlingworth Company" then bogus is appropriate --to my way of thinking. Most consider the term bogus to mean fake.
And in the North American marketplace there is nothing fake about The Sterlingworth Company. Literally thousands of companies do business every day using a name that is not registered. In no way does that mean the product or the people behind it are fake. Fox simply didn't want to devalue the brand name Fox by applying it to an entry level gun. His successors wanted to capitalize on the Fox brand for an entry level gun. Two opposing viewpoints, equally valid, depending on your objective. Those are marketing choices made daily by people running consumer product companies.