Found this advert on Car & Classic web site http://www.carandclassic.co.uk/car/C363162 In Germany, looks like it may have been used for hill climbs or sprints
Also this Upton engined sprinter http://www.carandclassic.co.uk/car/C481807 it not an Essex frame though
Also this Upton engined sprinter http://www.carandclassic.co.uk/car/C481807 it not an Essex frame though