A comment by Richard Barlow at the bottom of
"Vintage RTP Model":-
This reminded me of experiments with Jetex in the 1950's and I did find the "Farnborough In Your Clubroom" article in the April 1954 Aeromodeller
The month in which the Aeromodeller article was published came from Jetex.org where a Roger Simmonds article from "Sam Speaks" January 2004 was reprinted. At the bottom of Roger Simmonds piece there is a section on RTP, which brought up "200 m.p.h. at Knee Level?"
I couldn't find a scanned copy of the appropriate Model Aircraft but found another piece in Jetex.org.