A rose by any other name!
Sad thing is
This kind of testing (turn rates) was not part of the formal testing (read typical testing) during WWII.
That is to say you may find a few real world data test repots on a few planes but not all.
I do have these graphs for the IL-2 1946 planes here
http://www.flightsimtesting.com
Problem is right now I am updating my website for CoD, so many of the IL-2 planes (aka the data base) are not loaded right now. When fully loaded there are some 600+ planes listed