Thank you Cato,
Your help was invaluable. I'm going to leave it alone for a while, but "This is not over"! lol. I think I need some distance for a while to get a better perspective. I'm now getting on with a second concerto and I've taken note of all your advice and am trying to follow it with this next piece. That way, by the time I've "finished" that one, I hope to have learned much more and can apply it better to a further edit of the first concerto.
I'm sure many people would say, "just move on", but I'm trying learn as best I can and if I can make one of my favourite pieces better in some way after learning something new, then I will always want to do that, even if it's a couple of years from now.
Thanks again
Kind regards
Mark