This post picks up the finishing of the pilot model for the Speedwitch X32A parts set (or with Shadow Keystone; note: if you want to peruse the instructions for these sets, the linked file can be found via the two previous links.) The model was painted using Polly Scale light freight car red, followed by Polly Scale zinc chromate primer. I lettered the model with National Scale Car's set for the PRR X31/32/33. Weathering included some streaking using artists' oils, dilute washes and more artists' oils (especially on the roof to simulate pooling of sooty/dirty water, etc.,) plus application of PanPastels in select places. The chalk marks are also from National Scale Car. The placards on the doors are images of actual placards that I had printed on decal paper. The route cards are from Owl Mountain.
I found the base color I airbrushed to be a little too dark for the prototype so instead of repainting the entire model, I sprayed the center of the panels on the sides and roof with a lighter color, resulting in a shaded outcome that was appealing (to me, at least)
I added oils to simulate the spray from the wheels of adjacent cars
The underframe was one of the impetuses for this entire project