what do we know of these other three wheelers listed
Chris Rees's book "Three Wheelers A-Z" mentions (under "Hostaco Bambino Sport", a Netherlands-special open top version) that the Fuldamobil saloon was sold under the name Hostaco Bambino in the Netherlands, so that might be the connection?
The Tourette was of course produced by the Progress Supreme Co. Ltd, and therefore perhaps sometimes called the "Tourette Supreme"?
Chris's book also mentions (under "Tourette") that "A second three-wheeled model, the Car-ette, was stillborn". Sounds like it had a Schmitt-type layout, so shame I couldn't find a photo!