ΔE 8.9, close: similar, with a visible difference side by side. Smoke Gray is a little darker, more muted than Lederbraun.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Smoke Gray is a little darker, more muted than Lederbraun.
The same difference applies the other way round: Lederbraun 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 Lederbraun on the colour wheel See Smoke Gray on the colour wheel
All matches: Lederbraun equivalents · Smoke Gray equivalents