i have no facts to present, but companies like this often do extensive research and detail models of locomotives from various periods in time. note, for instance some GG1 prototypes that went through up to 1/2 a dozen or more liveries in their lifetimes. i would not write off the possibility that the prototype of this H8 class model did not display white lettering sometime in its career.
i have seen the Accucraft Allegheny running and while it has some flaws, i'll always take a live steamer over an electric locomotive in #1 gauge.