Mower identification

Growing up in a small, close-knit village in the '60s and '70s, there was always the opportunity of meeting interesting characters, but none was more of a character and played a more important role in my life than the father of my best friend. His interest in and enthusiasm for antiques, classic cars, engines, lawn mowers and pretty much anything that was a bit different has been a huge influence on me. I was recently given a photo of him on a ride on mower that looked to be quite unusual. Thinking back, I'm sure I remember him on it when I was a child, but of course I didn't pay too much attention back then. Anyhow, here's a photo. Does anyone here know which make and model mower this is?