Thanx for the info. John - I'll certainly check them out.Beachcomber, Paghco makes a near perfect replica of the flat head 45 heavy duty motorcycle frame. Might be what your looking for just google it and you have your frame.
However - after many non starts and broken promises, I've now found a guy that is prepared to work with me to build a frame. He is a coded welder and more importantly - a bike enthusiast.
His "day job" is welding up chassis [ multi-tube affairs ] for C Type Jaguar replicas and welding up alloy tanks for same.