Sorry to disappoint you Bri - I had never heard of it. When I saw the picture, I immediately thought the SGS-2-32's ugly sister and I was right.
Between November 7 and 10, 1969, the aircraft set a world closed-circuit flight distance record for piston-engined aircraft, in which it covered 8,973.38 miles (14,441.26 km) in 70 hours 15 minutes.
70 hours in a two-seat* glider - the mind boggles!
* Correction - it was a single seater! I thought the FAI had banned endurance flights - they certainly did with gliders.