According to some person on Instagram, the car was modified by Wood Bell Co. Ltd, manufacturer of BRS Wheels. While this person believes it was based on a Mazda MX-5 Miata (or Eunos Roadster), the windshield, doors/handles, dashboard, wheelbase, overall size, etc, all point to an S13-generation Nissan Silvia/240SX.
Of course, this person is probably wrong about the builder. (He's wrong about everything else.) The car was likely only placed on display by BRS Wheels.
The fact that it's LHD could indicate that it's a U.S.-spec 240SX Convertible. Between 1992 and 1994, I sold a lot of new 240SX Convertibles to exporters who would then ship them back to Japan. The U.S.-spec cars were imported as coupes (all with automatic transmissions
) and then converted here in California by ASC. For whatever reason, Japanese buyers were willing to pay a premium for them. I handled so many transactions to 'repatriate' these cars that I probably sold this one as well.
Pics are from the 1994 Tokyo Auto Salon: