The Elden PRH 11 Sports Racing car was designed for the FIA Group 5 Sports Car series and used a spare chassis that was originally fabricated as the Mk 7 Formula F100 but placed into storage after the Mk 7 project was sold to Clarke Sturgess.

The chassis was converted into a semi-monocoque by GP Metalcraft. However the proposed 1300cc engine was not powerful enough for the car’s weight, so the Mk 11 chassis was shelved.

The chassis was further modified in 1976 for Sports 2000 racing, where it was given black bodywork and raced by Works driver Chris Alford as the Saracen 77RS.