ΔE 8.7, close: similar, with a visible difference side by side. Russian AF Blue is a little darker than Interior Blue Soviet.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Russian AF Blue is a little darker than Interior Blue Soviet.
The same difference applies the other way round: Interior Blue Soviet is a little lighter.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Interior Blue Soviet on the colour wheel See Russian AF Blue on the colour wheel
All matches: Interior Blue Soviet equivalents · Russian AF Blue equivalents