I am probably going to get some as a birthday present! The other option is if anybody can fabricate a frame extension to join the side frame to the axle?
A backrest from A Wind of Change
The other thing I want to do is make a back rest, for comfort and I reckon it would also stiffen the frame - I know Popeye the Welder can do this but I don't have the skills! I think I will take a trip to Masters or Bunnings to see what I can botch!