Hi Nigel,
Great to see your pink Spitfire on the way. I did'nt find the time to start a new blue one yet, but I'll try to squize one in later this year.
Regarding the preshading - It's always tough to judge by a picture. It does look pretty ok, though. The paint appears to be a little on the thick side, but that just might be the reflections that makes it look that way.
My advise is to stick with the current layers and see what happens once you get the decals, the panellines, the wheathering and the final coat (satin?) on. By then, the preshading will probably be "barely noticable".
I also think it might be better if you get too much effect instead of too little, given that it is your first try and that you wish to learn for future builds.
I'm looking forward to see the finished Spit!
Cheers!
Ps. I spent Friday night at the Spitfire pub in Stockholm. Not a bad place to be...