It seems as if this may not be a problem in better climates than the UK but we need to solve the problem on two or three cars.
We have made the pressings that fit into the torsion bar tubes and the new bushes that are needed.
These pressings convert the end of the tube to the same dimensions as the 1965 to 1967 Torsion Bar Tube ends so it can be used with the smaller inner bush that Porsche still sell or with the UHMWPE1000 Polymer bushes we have made for competition cars.
The Rings fits on a spigot machined into the bush and acts as a tolerance ring between the bush and spring plate.
I will post a final photograph when we have them fitted and welded in place.