ΔE 7.6, close: similar, with a visible difference side by side. Leadbelcher is a little lighter than Dark Steel.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Leadbelcher is a little lighter than Dark Steel.
The same difference applies the other way round: Dark Steel 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 Dark Steel on the colour wheel See Leadbelcher on the colour wheel
All matches: Dark Steel equivalents · Leadbelcher equivalents