Thanks folks, your comments are, as always, much appreciated!
Today I have mostly been making a mess.....

I started off by taking the sanding sticks to the fuselage and removing the slight edges at the sides, and the large step underneath, where the two rear halves were joined. While I was at it I further sanded the rear half of the underside to reduce it's depth along the entire length. This also brought the angle where the slant up to the tail starts, forward to the rear wing spar, where it should be. All the remaining "detail" on the fuselage sides was also removed with the one exception of the inspection panel at the right rear of the engine. I had thought that the rear decking was correct, but unfortunately it isn't. The total distance from the front edge of the decking to the rudder post is now correct, but the area which has moulded detail for the turtledecking extends too far back, and the decking should be flat where it blends into the rear part of the upper fuselage frame - it is barely visible. To try to correct that I mad a small cut down from the top at the correct end point of the turtledecking, then sanded the detail aft of that flat. Small pieces of plastic card were added to bring the fuselage rear up to the same level as the end of the decking, and they will be blended in properly when dry. Finally on the fuselage I added fillets to the pilot's cockpit sides and they will also be shaped correctly when dry.

Since that meant I couldn't do any further work on the fuselage, I decided to start on the wings. I seriously thought about just scrapping them and scratchbuilding new ones - it would have been quicker and easier, they are that bad! But I wanted to see what could be done with the kit ones in case anyone wants to try this and isn't too confident with scratchbuilding.
So, out with a large knife and I started scraping. By far the easiest and quickest way to remove large amounts of plastic, but it does get messy - this is 1/2 hour's work and was just one side of the upper wing!

Another 1/2 hour scraping the other side, followed by 15 minutes with a coarse sanding stick, then the medium, then the fine, gave me this....

It's still a little thick, but it's a vast improvement, and if I take it much thinner it'll be too weak. So that's the thickness sorted, now I need to chop it up and correct the length......
Thanks for watching...
Ian