As Best I know the "ballroom cab" was a Crystal River construction to get their firemen out of the snow and rain…at least once in a while. There is the famous shot of her with the big cab on the D&RGW (no herald) just out of the shop in 1924…probably repainted from D&RG #432 at that time. There is even a shot of her in Dorman's RGS Ultimate: Modern pump, running boards, long cab, new tender. I will post the page of the photo when i get back to Ogden from Wyoming. The long smokebox, short cab version, with a #346 style smokebox front and a round number plate (!) is in Dorman's Durango 2nd edition. seems to be late 20s or early 30s. By the late 30s she had the modern appearance but no visor on headlight and a toolbox on pilot.
this is about all I know plus sone assumptions. If anyone else has anything to add, please chime in.
DW