There were two Boy Scout rockets fired on April 27, 1960. The rockets were launched at Raeren, Belgium.  One was the Dan Beard rocket and one was the Baden-Powell II rocket.

There were a total of 90 covers and Astrograms flown on the Baden-Powell II, including 50 Boy Scout FDCs from the Canal Zone dated 8 February 1960.  The flown covers were signed by Dr. A.J. de Bruijn.  The cachet (round one on left of cover as you look at it) identifies which rocket the cover was flown in.

The Scout local issue rocket stamp in the upper right corner were both perforate and imperforate and printed in sheets of four.

Ellington-Zwisler Rocket Mail Catalog,
American Air Mail Society, 1967
Dr. Max Kronstein, Rocket Mail Flights of the World to 1986
The American Airmail Society, Cinnaminson, New Jersey 1986.