After gluing the underframe to the body, I put some blue painters masking tape over the inside of the window openings of the body. This will prevent exterior paint from coming into the already-finished body interior.
As shown here, I put the same masking tape over the under side of the car. This was quite a bit more difficult due to all the underbody details that were already installed. I first placed a strip of masking tape on my glass work surface, and then ripped it up from there and placed it on the model. This removes a bit of the glue from the tape, so it won't mar already painted surfaces. I also put masking tape over the top of the open body to reduce over-spray to the interior. Again, this was a bit of a challenge, but I was successful by being careful with the aim of the airbrush during the painting session.
I airbrushed the exterior using ScaleCoat paints, a mixture of 5 parts "Bright Red" and 2 parts "EL Maroon". This came from the Bowser web site's HO-scale paint guide (appears to no longer be available online). This was the first time I used ScaleCoat. I think I like Floquil and Polyscale paints better for airbrushing. The one big advantage of ScaleCoat is that it gives you a glossy surface, so you can start applying decals immediately after the paint is dry. Over all I am happy with the results, though. I do think, however, that the color is a bit too red. Yet, studying prototype photos, I have seen colors ranging from freight car brown, to red, and to bright orange. After I let the paint dry overnight, I hand painted the grab irons and the step edges with Floquil's "Reefer Yellow". That required a very small brush and a very steady hand.
For the decals I bought two sets (the minimum per order) from Greg Komar (he has closed his business, so they are no longer available, except through the secondary market, perhaps). I bought PRR set #341 "Pennsylvania - Cabin Car Classes Nd, N6A, N6B, N5, N5A, N5B, N5C. 1926-1955 Lettering Scheme, White Lettering. No Herald". I applied the decals to the model using a mixture of 50/50 distilled water and Walters Solvaset. The decals are very delicate and must be handled with extreme care. After the decals were applied and had dried for a few days, I gave the whole car a spray of Testors' Dull Coat to protect the paint and the decals.
After letting it all dry for a few days, I installed the couplers and the wheels. I put some weathering chalks on the side frames of the trucks. The couplers required a bit of trimming along the body parts to make them fit.
I also put a conductor in the car to liven it up a bit.
I placed the roof on the model and put the whole thing on a digital scale to weigh the model. The car weighs 4.9oz (138g) which is about right for this 6-inch model. Some weight will be added later on when I install the electronics to light the interior and the marker lights.
The final step now that everything is done, is to install the window glass. I am using some very thin clear plastic I bought from Clover House years ago. It has a thin film strip on either side, which prevents finger prints from getting on the plastic while you're handling it. I cut and trimmed the pieces to fit the window openings and then glued them in place using Formula 560 "Canopy Glue". This photo shows two pieces being glued to the side of the roof.
Early on in the construction I had installed the air hoses, which needed to be removed to be able to install the brass end walls. I drilled a hole in the plastic end of the end wall and superglued the air hoses. I decided on the P-B-L ones (part no. PBL-555) because they are made out of actual rubber, just like in the real world. This close-up photo shows one of them installed.
This photo shows the completed model, with all the glass and the air hoses installed.