Ed from RcCrafters was very accommodating with the addition of an aft brace. He sent me the STL files of his CAD design and I simply threw them on the printer (with supports) for a PLA print. Not particularly suited to a 3D print, but really handy to work out what fits.
Quick 3D print from RcCrafters STL file of Ed's CAD design with the aft brace in place
Fits fine, just some minor optimisations before the final design