Re your project, I hope the following & log book notes will be of help:  (I would add that the following comments on the comparative BKB/Skylark 2B glide angle were based on very limited (unplanned) comparison flying between the two aircraft.  Obviously, no quantitative data was obtained but (at a guess) the BKB was about 10 Knots faster at its best mid range speed.)
      To my knowledge, the basic concept, design and construction of the BKB-1, (registration CF-ZDK-X) was carried out by three partners in the project; i.e. Stefan Brochocki, Fred Bodek and Witold Kaspryk.  My understanding of the design work-share was that the theoretical work on the aerodynamics and basic stress work of the design was carried out by Stefan, with mechanical design contributions by Fred, and practical glider pilot inputs from Witold, who was a very accomplished soaring pilot.   The BKB-1 appeared to be a very efficient design aerodynamically since it could out glide a then current good glider which had twice the aspect ratio and 10 ft. more wing span.  However, more work was required to improve controllability as noted.
       The following flights and comments were recorded in my log book during the aircraft's flights made at Hawkesbury airfield, Ontario, Canada over a three year period:
 
1961 
May 13.  Two flights 16 minutes & 18 minutes.  First flights in experimental swept wing tailless glider.  Extremely sensitive in pitch.  Directional stability reasonable except for small angles of yaw (approx. 5 degrees  deadband).  Heavy aileron drag (elevon).   Air brakes (both rudders deflected together) ineffective.  Individual rudder  effect good. 
May 14.  One hour 49 mins.  First soaring flight.  Rudders effective in initiating turns.  Soared BKB-1 with own Skylark 2B (ZDL) flown by R.Halliday. BKB-1 appeared to be much faster between thermals with a flatter glide angle in the 50 - 75 knots region.
May 20.  Fourteen minutes. 
May 27.  One hour 56 minutes.  Height of 6600 ft. max.
May 27.  15 minutes.  Landing practice.
May 28.  1 hr.52 mins. BKB only glider with enough penetration to stay around field in 30 MPH wind.
Sep 23.  15 mins. 
Sep 24.  18, 20, 20 mins. (Three flights).  Landings on rough grass field cause porpoise type bouncing which can be divergent as aerodynamic control is reduced. 
Oct 1.   15 mins.  Landing techniques investigated.
Oct 7.   16, 12 mins.           "
Oct 8.   22, 15 mins.           "
Oct 9.   30 mins.               "

1962
Dec 1.   15, 11 mins.  First flights with new full fuselage length landing skid to reduce noted bouncing tendency on landing in rough terrain.
Dec 2.   22 mins.   Photography.

1963
May 4.   22, 12 mins.
May 5.   55 and 1 hr.46 mins. 
May 12.  27 mins. and 2 hrs.54 mins.

TOTAL TIME:     17 Hours 11 mins.