The SR53 had a de Haviland Spectre rocket motor of 8,000lb thrust and an Armstrong Siddeley Viper turbojet of 1,750lb. The surviving example in the RAF Museum is
shown here
The SR53 was a 2/3 (?) proof of concept for the SR177. This was one of the many UK designs that never reached production featured in the 50th Anniversary RAF Yearbook - the 177 looked like the Lawn Dart complete with underslung intake. A view of the aircraft is
here