Richard
Many years ago Rob Baker, one of the founding members of the Cobra car club built both a body and his chassis from scratch.
Rob now lives in Mornington, Victoria and works for the Ambulance service. Someone may be able to give you some clues on how to contact him. Or ring the ambulance service and they may assist.
alternatively try CS.
He may draw one up on a glove box for you for $100
Bernie