David,
I should explain why I am asking. There is a part which Bristol called a "distance piece" which sits above the front coil spring. I don't know what the original ones were made of, but they disintegrate over time and if one side goes before the other it would make that front corner of the car drop slightly. It is part No.10 in
this diagram. The lower "spring seat" part No.15 is made of the same material and also eventually disintegrates.
You can see the new versions of these parts, (purchased from Bristol), in
this thread . You may notice there is also a black rubber piece in the picture in that thread - I believe that was added on the 411, but would be worthwhile adding to the 408 if you need to refurbish the front suspension.
Kevin
PS: Re-reading my old thread on this topic, it was actually the steel plate between the rubber and the distance piece that was a later addition, not the rubber piece.