IIRC the flying prototype was 105 pounds dry, but the last changes to the crankcase and rear accessory case will probably add 2 or 3 to that number.
There are many many different airplanes that could benefit from this engine:
Anything that would have used a 45-60HP Volkswagen derivative, the 503-582 Rotax and similar size 2-stroke engines, anything that would have flown well with that 2 cylinder Franklin, any of the antiques that used the Continental A-40 or A-50, or the E-113 Aeronca engine, probably half of the (short list of) airplanes that successfully used the 55 and 65 HP Lycoming O-145, and perhaps even the smaller/lighter 1/3 of the airplanes that used the Continental A-65.
The 2 seat Cubs, Champs, Luscombes and Taylorcrafts... NO.