While looking for info on the performance the La-5, I stumbled on these two very interesting books listing the aircrafts and engines produced in USSR between 1917 and 1945. They include a lot of info on mainstream aircrafts of the time, but also on more obscure ones that we don't hear about a lot about. The only downsides are that you have to subscribe to download the files, and that the scans are incomplete a few on pages detailing aircraft performances.