Hi sleipner,
The national fighter values are not listed in the rulebook - only on the air-to-air battleboard (and on the national reference charts for the major powers). "Others" on the air-to-air battleboard refers to all non-listed nationalities - including 'minor' powers that have air units (so the Polish, Spanish, Turkish and (yes, unfortunately) even the Swedish air units are considered "early war" 2 or less air-to-air combat value.
It is the same unit for the French. If they are still in the game in 1942 - the French air units automatically upgrade (of course, as pointed out by others, if the French are still in the game in 1942, the game is probably over
)
The date for the Soviet air units on the air battleboard is misleading (thought it usually works out around 1942). The Soviet’s can start building mid-war air units (and can no longer build early war air units) after they have built two additional early war fighters – per their production chart – regardless of whether they are at war or not.
Sorry for the confusion – hope that helps.
Mark