100 hp total should have been adequate, if they achieved the target weights. That would have been difficult with 1950s metal airframe technology. Maybe that is why we haven't heard anything since.
A comparison of max weights of small twins:
Stark 201: 2 seats, 841 kg target (? airframe, 100 hp total, 8.4 kg/hp)
Wing Derringer: 2 seats, 952 kg (metal airframe, 320 hp total)
DA42: 4 seats, 1252 kg (composite airframe, 336 hp total)
some single engine low power airplanes:
DV20, 80 hp, about 750 kg (9.4 kg / hp)
Cessna 140, 85 hp, 658 kg (7.7 kg / hp)