I have done an experiment with a pic of Mk.IIa fitted with an exhaust of Mk.IXc.Look at the photos.The first one is authentic.The second pic looks a bit strage for me, doesn't it.Perhaps I'm not an artist but there is something a little wrong.As far as the flying only Mk.IIa with twelve exhaust is concerned,I think that there is no matter for many people if the spit has 6 or 12 pipes.Personally,it is ridiculous that there is no possibility today to restore an aircraft precisely.But I've seen so many strange an funny things about planes that I'm not surprised.Have You ever seen the last movie about Pearl Harbour ?.One of the main characters was fighting as a member The American Eagle unit during BOB.Spitfires, in the film, were coded with RF letters.As I know the code belonged to The Polish 303 squadron equipped with Hurricanes in that time.Or Spit Mk.IX with a earth brown-dark green camo pretending a polish MkVb one.Strange,isn't it.
Spitfire Mk.IIa
source unknown.