Well, problem solved, with reassuring advice from Peter B.
As we are all aware, the critical point to aim for is the rebound springs JUST kissing the stub axle assembly, so that it is only just possible to rotate the spring by hand, (assuming its not stuck or gunged up).
The installation instructions suggest a good starting point for a modern plus 4 with lower ground clearance, is to have about 30mm of spare thread showing above the adjuster rings. This is where I became concerned as I expected the rebound spring to relax within maybe 10% or so of that measurement...but the eventual correct setting was only 10mm. (It’s a Morgan, sir...!)
New kingpins and SSL were fitted 5k miles ago and I was advised that it was set a “bit on the tight side” and would probably bed in. However, I have never been able to see a relaxed rebound spring since it was done. Incidentally, the spare thread was set at 28mm by the installer.
My method was first to unwind the top adjustment completely on BOTH sides, do several bounce tests with shockers removed and then I could see a good few mm of slack had appeared. Then by screwing down a few mm at a time, doing bump tests, rotating steering to ensure settlement, I arrived at 10 mm of thread showing. I have also reset the shockers to 5 clicks above soft (previously 9) and everything seems fine. So it appears that I have never experienced the true feel of SSL since its installation!
Extremely grateful to Peter B and hope this will help others who may find a similar predicament.
