ΔE 6.8, close: similar, with a visible difference side by side. Dry Rust Brown is a little darker, more muted than Rust.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Dry Rust Brown is a little darker, more muted than Rust.
The same difference applies the other way round: Rust is a little lighter, more saturated.
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 Rust on the colour wheel See Dry Rust Brown on the colour wheel
All matches: Rust equivalents · Dry Rust Brown equivalents