Many thanks for looking in folks, as always your comments are much appreciated.
Weeeeeeeeeeell……………………I'm going to call this one done, it has turned out reasonably well but became a bit of a pain towards the end and I feel I could have done better. All the fiddly bits were excessively fiddly and in the end just got thrown together. So not one of my best efforts.
So here's a bit of a preview and I'll do the finished thread in a day or so.