Homebuilt version of the 1944 BA-4. The BA-4B first flew in 1966.
"The Andreasson BA-4B was a single-seat aerobatic biplane marketed for homebuilding.
Design and development
It was based on Andreasson's pre-war BA-4 revised to take advantage of more modern construction techniques, such as the use of sheet metal in place of the original's all-wood structure. It was a single-bay, staggered, equal-bay biplane with fixed tailwheel undercarriage. It was offered in the UK by Crosby Aviation and in the US by Larry Karp as the Canary Hawk."
Source: wikipedia.org
Photo: hobby.se, SFF Bildarkiv