gte4289's identification is correct so I've awarded him a point and moved this to solved. It's the mid-engined (3.5-litre V6) Bolwell Nagari Mk X (now known as the Nagari 300).
I don't suppose gte4289 will be aware of what I've done since he hasn't logged on since March 2017 either...
But it does clean up this geriatric puzzle, as it seems 58_spyder is not coming back (last logged on in August 2016).