.......First off the name is Spar not Buff, never was Buff.

There is no perfect match possible as period pieces at the Navy Museum at the Washington Navy Yard did not match each other and different layers exposed by chips and scratches showed differences between layers. Some pinker, some yellower, some browner.

That said matched to a mix per Painting and Cementing out of the bottle Vallejo Model Color Goldbrown 70.877.

Within the variation of period pieces-
Vallejo Model Air Yellow Ochre 71.033 or US Interior Yellow 71.107
Tamiya XF-3 Flat Yellow and XF-15 Flat Flesh 1:1

To the yellow end AK11117 Golden Brown. To the tan end AK 11116 Tan Yellow. They are within the extremes I observed at the Navy Museum.