ΔE 8.8, close: similar, with a visible difference side by side. Gold Rush is a little lighter than Skullcrusher Brass.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Gold Rush is a little lighter than Skullcrusher Brass.
The same difference applies the other way round: Skullcrusher Brass is a little darker.
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 Skullcrusher Brass on the colour wheel See Gold Rush on the colour wheel
All matches: Skullcrusher Brass equivalents · Gold Rush equivalents