After leaving the remains of the seal submerged in CRC Penetr8 (the closest I could find to Plus Gas) for a week I tried the usual method but no difference. I think one of the bushes is now jamming the stanchion so I can't get enough of a whack to budge the seal when I try pulling on the stanchion. The rubber of the seal is basically f*****d and picks out easily with a screwdriver and i've now removed most of it.
My next move is to get the dremel and try cutting out the remains of the metal part of the seal directly below the groove where the retaining clip sits so that I'm not working too close to the stanchion itself. This will leave something akin to a washer which should be easier to get moving. I'll push the stanchion in as far as it will go so that if there's any damage it will be (hopefully!) outside the range of normal contact with the rubber of the (new) seal.
Such are the joys of motorcycling!!
