Okay I believe I've found it!
Your confirmation regarding Tom_I's post that it was based on a Triumph Spitfire started me trying a Google search without luck - unless I was suffering from a surfeit of Spitfires.......
I then tried narrowing it down by specific models and eventually came across it on page 17. (thank goodness, perseverance pays occasionally)
It appears to be based on a 1971 Mk 4 Spitfire with a Datsun 'A' engine built by the man who created the Datsun Super Samuri, namely Spike Anderson.
He now lives in Spain and has long had a desire to own/build a 1930s style sports car for enjoying the Spanish sunshine.
He is also building the 75th and last Super Samuri for a friend in Spain after importing a 240Z into the country.
I also noted with interest that he has co-written a book on the Super Samuri - a book that will now be on my shopping list.
As to the puzzle car, it doesn't appear to have a specific name but I guess it could be called Spike Anderson's Samuri Special based on a Triumph Spitfire Mk4 with a Datsun A engine.