I can't find anything about this so, if I'm duplicating old information, my apologies.

The outstanding detail drawings of the Spitfire MkIX and Mk XVI that were printed and sold by Paul Monforton have sold out so, he is now selling the drawings in several scales downloadable in DWG format.

He is also offering his book Spitfire Mk IX & XVI Engineered as a downloadable PDF while the hard cover book is still available.

There is no better source of data on these Spitfire marks that I know about.

http://www.monfortonpress.com/