Thank you, Fencer.
Devil, here is the text from Joe Baugher's serial number site. It shows that 42-28473 was initially in the 56th FG:
28473 (MSN 2135) 61st FS [HV-P], 56th FG, 8th AF, Boxted, Station 150; "Big Chief"; 410th FS [R3-F],
373rd FG, 9th AF; "Dorothy K". In mid 1996 was with Planes of Fame (East) at Minneapolis as NX47BP
It does omit the aircraft's time as "Ruth II", however. But we have clear photographic evidence of 228473 as "Ruth II".
I want to be as accurate with skins as circumstances allow. In this case, we have a WWII color photo, B&W photo, a few artist's color profiles, model box art, model decal sets, and a discussion of the scheme at Britmodeller website.
We know the aircraft came over from the 56th FG, and spent some amount of time as "Ruth II", with a wide, dark cowl band. (I think it's likely "Ruth II" was painted in Red). This band seems wider to me than the 56th's red cowl, but does seem to match the width of the black bands painted on unassigned aircraft by the facility at Burtonwood. (not sure if she may have spent rehab time there after the 56thFG, before being transferred to the 9thAF?)
We know the dorsal fin was a field mod, added after her time as "Ruth II". We know the B&W photo shows her at an earlier time than the skin depicts, since the kill count is lower, and the nose art script "Dorothy K" is not present, or at least obvious, and the arrow piercing the heart is missing.
Of all these details, the most important resource I think we have is the period color photo. This does seem to show a wide dark section on the top front cowl, which could be consistent with the wide dark band from "Ruth II". Model makers and the IL-2 skinner have settled on the band being black. The B&W photo challenges this assumption, but I think the color photo, being more recent, has precedence. I think its clear from the color photo its not a red band left over from the 56th's red cowl band.
Also, as much as I like the look of the red & yellow checkerboard on the shield from the color profile, the WWII color photo doesn't show any red-orange on the shield. It appears to be a yellow & green checkerboard with a yellow diagonal stripe. So I'll make that change too.
This will also be consistent with the IL-2 skin and Eduard model.
The color photo vs the B&W also settles the debate for me on the color of the tail flash. The skinner and the model show the flash as yellow, and the B&W photo indicates a light shade such as yellow, but I'll stick with the dark blue as it appears on the WII color photo.