Francillon gives the following:

Rotor diameter: 31' 9" (9.45 m)

Length: 20' (6.1 m)

Height: 9' 3" (2.74 m)

Empty weight: 2,450 lb (1,111 kg)

Loaded weight: 5,000 lb (2,268 kg

Max weight: 6,300 lb (2,858 kg)

Rotor loading: 6.6 lb/sq ft (32.3 kg/sq m)

Max speed: 138 mph (222 km/h)

Cruise speed: 109 mph (175 km/h)

Rate of Climb: 2,400 ft/min (12 m/sec)

Hover Ceiling in Ground Effect: 12,000' (3,660 m)

Range: 98 miles (158 km)

It's roughly 40% of the size of the K-Max with 42% of the load capacity,

really not too shabby for the period.