This was introduced by Aeromodeller thus:

One of the free plans given away with this magazine in June 1939 was a twin-boom all-balsa machine powered by the so-called 'penny rocket'. The drawing is reproduced here and no instructions are necessary but it worth quoting the following. "As rocket mixtures are difficult and dangerous to prepare unless you have previous experience with them. I am recommending the ready-prepared type, which may be bought at most toy shops for a penny."

Photocopy this plan to give 22 inches span, cut parts from 1/16 inch sheet (1/8 inch for booms and nacelle) colour blue and white to recreate this 1939 Aeromodeller design.