Yes, indeed, it was built by Robert Cutts.
This puzzle dates from long ago, and I recall delving into it and finding information on another site as well, which did say it was a Sportsman Coupé originally, which is what I wrote in my file on this, although I think it would take some finding again.
I also reached the conclusion the body used was a Microplas Stiletto.
So, WayneB, you get your first Professional point for this one!
Well done, though I think without the words "Sportsman's Coupé" to Google I don't think you would have been able to find this, so I'm giving a point to Allan L as well for doing so much digging and finding that.