Looks promising Kazan. A couple of things you might want to look at though.
The squadron letters need to be made smaller. Looking at the photo they should be roughly half the height of the fuselage roundel. Also the Polish Airforce emblem on the nose should be a bit bigger.
Maybe you could tone down the rivets, particularly on the wings. The wings were flush rivetted on the Spitfire, but the fuselage had normal rivets.
BTW Obie, best bet to see what skins are already done is to look on the Netaces pages. There is an up to date list there with screenshots.