Nearly seven years late but here's the data on the BOK-3. The BOK-3 was built in 1933 as a four-seat liaison aircraft with side by side seating (it was also known as Tsebrikov BOK-3 utility/liaison aircraft (see https://www.secretprojects.co.uk/threads/tsagi-zavod-39-tskb-designations.7286/)). It featured a semi-monocoque fuselage, with ply covered wings and fabric covered control surfaces. The sole example first flew in 1933. A number of variants were planned including a crop sprayer/seeder and a military trainer. The latter was to be fitted with a fixed forward-firing PV-1 machine gun and a manually operated turret fitted with a single DA machine-gun with provision for a single FAB-100 100 kg bomb or a reconnaissance camera.