So having trimmed off some bulk material, it was time to do some carving. I attached a rough grit car paint grinder to my angle grinder and set to work. It worked a treat. Fast and suprisingly accurate. I wouldnt use it for anything fine, but as a tool for getting the shape fleshed out it is marvelous.
Rear stay sections rough positions.
Rear stay sections.
Getting the symetry to work on this has been a challenge. The parts do not have to be identical in shape, but the points at which they meet the frame and the wheel drop outs do need to be very acurate. So the stay arms will be a little organic in shape, but the wheel will (all being well) sit true to the main frame.
Video clip of the rear stay work in progress.