Hey guys I found some more info which points the car more toward David Haynes (not John, sorry I misheard my Dad )
Here is a pic of him standing on the side of one of his Model T's in the 50's/60's, this one appears to be very similar to the one parked behind the Delorean.
Also, after showing him the pictures, my Dad said the piece of paper behind the windscreen on the drivers side is possibly what remains of the information card/plaque Haynes had near the car detailing its history and so on when it was in the showroom.
Nothing reliable or concrete, but it does make the story a little more interesting