I think we can all agree that, whatever it IS, it IS NOT a 1964 S2 and never was. I'm going to go with it being an early-ish Caterham with a Franken-yotaed drivetrain. Those rear trailing arms are, uhh, interesting, as are the front swaybar links. Speaking of which I think the front suspension has been given the wide track treatment. There are rose joints everywhere. The RH steering rack boot is still in shambles. The front wheels may have been redrilled for a different bolt circle.
Gauges are a mix of this and that. The dash panel might be a completely replaced panel. The turn signals occupy two of those toggles?
I'd honestly be afraid of this car.