An update on what has been happening. The Wilbers springs arrived from ASR after ordering them on the phone and it was agreed K100 standard springs were the ones to go for. They arrived two days later and it says K75RT on the box. I thought "what the hell" so I e-mailed Greg not very happy he had sent the wrong springs but he e-mailed back saying he thought the heavier rate springs from the K75RT would suit my weight better (95kgs). In the meantime k75cster helped out by loaning me some snap rings for the fork caps, thanks very much Keith. The bike had been lowered 30mm by the previous owner but the plastic spacers that had been fitted looked as though they had been just cut off with a hacksaw and weren't very square and therefore not the same length all around. So I had a mate with a lathe face them up so they are now 25mm long instead of 30mm. So in with the new seals from MotoBins, re-assembled the damper rods and put the forks back together. The fluid height recommended by Wilbers is 170mm from the top of the fork tubes with the tubes pushed fully home inside the lowers but because of the 25mm lowering spacers I took that back to 145mm. Wilbers also recommend 15wt fork oil but seeing on had 10wt on hand I tried that first, actually 10wt is recommended for the K100 springs so why the 15wt for the K75RT I am not sure maybe because of the fairing? It took quite a bit to compress the pre-load on the springs I would say more than the 40mm max that Wilbers recommend. Forks back in the bike with R series fork gaiters fitted from MotoBins. Pushed it of the stand and immediately noticed not a lot of static sag in the forks, probably 15mm or so. Out for a test ride and the first thing I noticed is the bike is a lot less ponderous at low speed and riding out of the yard you could feel a difference straight away. Overall on the road the bike feels a lot more secure, planted and stable and the steering has slowed a bit too not having the nose down so much, the 5mm off the spacers probably help a bit with that as well. The ride quality which was a top priority is also very good and reaction to sharp bumps is quite good, one reason I tried the 10wt first. All in all the effort has been worth it and I can definately recommend the Wilbers springs. Another thing with the lowered forks is that it cuts back the amount of travel so the overall movement is a touch over 6"

Good to know it all worked out, glad to be in a position to offer the snap rings and the manual when needed

It seems you have solved your issues, good one. As an afterthought, could you have used a, possible shortened, snap ring from the fork seals? Or one from another bike? BMW R-type or other?