But I've found this.
\Coomb\, n. [AS. cumb a liquid measure, perh. from LL. cumba boat, tomb of stone, fr. Gr. ? hollow of a vessel, cup, boat, but cf. G. kumpf bowl.]
A dry measure of four bushels, or half a quarter. [Written also comb.]
So perhaps 2 coombs in a quarter rather than quart.