Hi Gamary,
As you know I have been developing my spitfire for what must be 6 years and I can still pick fault with it compared to other peoples line drawings. That said, mine has not been constructed using any line art what so ever. I did it once that way and had to start over. I have been watching your progress with my lip firmly bitten, I don't consider myself to be either an expert or to be absolutely right on any artwork I produce, but I do get my artwork to a point where I can sit back and declare it "believable" in my opinion. I tend not to comment on peoples work these days, I am just another Joe who does a bit of drawing, that's the only connection I have with what I draw, so who am I to say what's right or wrong? I am however a big fan of your work and I love your style.
I would check the shape of your nose area from the firewall forward and also the shape of your vertical stabilizer and rudder.
Your spinner looks slightly over sized to me also.
I am not overly sure about the Volkes filter with the Vb airframe either, but I might be wrong on this point. I thought they were fitted to Vc's only.
Here is a link to my conclusion, I hope it helps.
http://premium1.uploadit.org/JeSTeRs//20p-Spits.jpg
And please feel free to totally disregard, it is after all your drawing.