My suggestion for the Polish and Czechoslovak tech tree for War Thunder. Feedback on Reddit welcome.
The tree includes vehicles from Second Polish Republic (1918–1939), Polish People's Republic (1944-1989) and Third Polish Republic (from 1989), but also from Czechoslovakia (1945-1992), Czech Republic (from 1993) and Slovak Republic (from 1993). Updates are expected.
I don't plan on adding projects of which only mockups were made (such as TS-16 or PZL-230 Skorpion).
In order to check the aircraft's nation, click it and check the 2nd slide and its description.