Crayford were known for their conversions to manufacturer's existing cars. While a number of nicely converted Imps exist, a Crayford job could well be superior, as they have been in business for a long time, and would know where to add strength.
There is reason to believe that they produced three convertible Imps, although no official Crayford records mention them.
Crayford may have produced three prototypes for evaluation.
At least one was spotted in a barn with an official Crayford Chassis Plate (with the figure 003). It was in the late 70s in the Hereford area. This imp, laid up in a farmer's barn, had a soft top.
Crayford Convertible Car Club
Imp Cabriolet in three weeks / John Crompton, Chelmsford, Essex. - Impressions 1991, December. - p.19-21
Will Kee...'s convertible
Mind your head - Tim Haynes' site
Dave Turton and John Summerfield brought their unfinished convertible Imp to the National Weekend of 1991.