This is the successor of the Gold Head, the 60-FSR brought out 1974 (first Schnuerle OS 60). Weight is 470 g / 16.6 oz w/o muffler and 590 g / 20.8 oz with. Power as specified 1.7 hp (maybe without muffler) but realistic (with muffler) is 1.27 hp at 13800 rpm. It may be propped to lower rpm giving good torque.

An interesting point is a hint in the original instruction leaflet: If no muffler pressure is used one should use a carburetor inlet (smaller diameter, more suction) for the 7B carb or use a Perry carb. Might explain the big carb opening?