You can still get the ABS prefabricated guards for pre superform wings, advertised in Miscellany. (Blackphey@hotmail.com)
There are other fixes. I use neoprene over fibreglass circuit board as mudflaps just to the rear of each wheel. Steve Wells won the Innovations at Buxton with a complete underwing shield, similar to the ones advertised in Miscellany but for Superforms.
You could probably adapt some modern PVC liners for the rear arches
