Hi! I know that in the late 60's Harold de Bolt made some planes that looked quite similar to his pattern ships, but were optimized for pylon racing purposes.. Dave Gierke also drawn some similar models.. Anyone could give me some additional info about these planes?
(hope to haven't placed my post in the wrong fourm..)

The Encore was a late 60's deBolt pattern model that used design characteristics from his racing models, most notably a very compact, streamlined nose with "cheek cowls" on either side. A few years before his Interceptor series featured a tightly cowled inverted engine and a streamlined platform.

His late 60's racing models (the AMA class was Formula 2) included the Continental 600, P-39 Cobra and P-51 Mustang; both of those could be considered sport/pattern and flew very well. deBolt's Formula 1 designs such as the deNight Special and Midget Mustang were pure racers.

Hi! Thank you for your reply! Do you know where I could find the plans for the P39?

Actually yes, plans are readily available from the AMA website. I'm almost certain they could handle overseas shipping.

It's listed as the "Live Wire Cobra", wingspan is 58".