Thank you for your promt response Bob. It’s all coming clear now and what a fantastic service from UKWA. Given that the pin has no mast supporting role does the mast just sit there standing on the foot held in place by the forestay and shrouds. If so I guess the chocks then come into play. I don’t have any of these but I’ve seen elsewhere that they can be easily made up. I wondered if the rubber tapered door stops you see might work in a pinch.
With regard to R Clips. I have found a selection of these, at Fox’s Marina Ipswich, down to a size (and smaller) that fits through the hole in the lower rudder pinacle. I felt that was a good idea!
With thanks Paul