[Franek Grabowski]

Graham
I agree that both Spitfire and Hurricane were extremities. I assume Camm believed the thicker airfoil will allow to hide armament, thus reduce drag, otherwise the goal was climbing and not horizontal speed. Whatever, it did not turn to be good idea.
My point is that any modifications to the fuselage area were much simplier than in any other semi-monocoque aircraft and no structure modifications were needed. Despite that, nothing has been done in that direction up to the end of production in 1944. Malcolm Hood, Fw 190-like canopy, there were many possibilities that could substantially improve visibility. Note, that teardop canopy was proposed by Quill already in 1940 and only because of fear of production stoppages it was introduced in 1944. The same with Mustang, new canopy was introduced when need of other major modifications arose. In contrast, Hurricanes could have been converted in a Maintenance Unit.
Tornado or Mustang were indeed later designs, but please note the design started before the experience was gained. Despite that, there were several aircraft of the period, like Airacobra, Fw 190 or Zero, that had pseudo-teardrop canopies with much improved vision.
The idea was around but I do not see even attempts to implement it. While I can understand your arguments, I am still surprised, that is all.
Concerning fabric cover of the rear fuelage, my understanding is that turbulent airflow caused quality of the finish less important, but it does not mean it is not important at all. Thus perhaps no major gain in speed, but still some improvement, also in maintenance.
Finally about Spitfire vs Yak. Yugoslavs did a direct comparison of a Yak-3 against Spitfire VC Trop., and found them just equal oponnents, Yak being better in vertical and Spitfire in horizontal manouvers. Similar conclusions were drawn after a combat between Lightnings and Yak-9s over Yugoslavia in 1944, the outcome being unfavourable for Yaks in ratio 3:1 I think. Also Mustangs fared extremelly well against Yak-9s in March 1945, downing several of them with no losses. I know Polish top scorer, Skalski, who flew most of the fighter Merlin Spitfire variants, as well as Mustangs, had a veeery reasonable opinion about Yaks. Unfortunatelly, as yet I was unable to find any detailed description which would point out weak points.

Kari
Take it easy! My point is that we should have some marigin for possible error in identification. It may turn out that some of the sluggish Hurricanes were Yaks actually.

Igor
Remember about logistics. Both Finns and Rumanians had quite limited number of aircraft available and limited spares' supplies. This seriously limits possibility of extended opartions with such aircraft, with rather sophisticated water cooled engines.