What else could one build around a 50 hp Limbach L550 ?

Here is the pinnacle of WW II fighters a F8F-2 Bearcat in 40 % size.

Highly tuned Bearcat " RARE BEAR " for time being is the world's fastest piston aircraft with 528 mph ( 850 km/h ) average speed.

40% size F8F-2 would have 3.75 m2 wing area that is marginally larger than MAX III sports now.

AR-5 that is the previous FAI 300 kg class world record holder is based on Bearcat design ( more or less...it was studied when AR-5 was created ).

http://www.ar-5.com/

Arnold AR-5 pages have one of the web:s most complete study of a record setting AC. It is well worth to read if interested in aviation.

Here is a comparison between Ar-5 and Vari-Ez. Both are 14.5 ft long. That is just one metre more than a 2/5 size Bearcat is.

http://www.ar-5.com/sportav93.html