ΔE 7.8, close: similar, with a visible difference side by side. Imperial Gold is more muted than Top Brass.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Imperial Gold is more muted than Top Brass.
The same difference applies the other way round: Top Brass is 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 Top Brass on the colour wheel See Imperial Gold on the colour wheel
All matches: Top Brass equivalents · Imperial Gold equivalents