I can't point you to any prototype photos, but I've got a couple photos on my website of my models. I have three dozen of the Bowser models, three different schemes in 12 numbers each, and they are mixed into two trains.
One thing I'd highly recommend is the detail kit for the Coupler Mate made by Plano. It really sets the Coupler Mate apart as a model in its own right. Don't forget the drop grabs on the Coupler Mate, too.
Adding metal wheels makes a major difference in the way these models perform, so don't forget them.
One of the most important "details" I've added to my Roadrailer models is painting the highway wheels. There's really nothing to it. I spray the entire wheel white with the airbrush and I don't worry about overspray on the tire. Then I paint the tire with a brown/gray/black mixture while twisting the half axle/tire assembly in my hand using a brush. Finally, I use a fine brush to drop a slightly thinned black into each wheel hand hole. That's really the key to getting the wheels to look good. See here:
http://www.geocities.com/norfolksouthernhinose/TCSwheel1.jpg
Weathering on these trailers is heavy for highway trailers, which are clean by comparison to freight cars, but that still means "heavy" is a freight car's "moderate" weathering. The spray from the railroad wheels leaves two feathered vertical streaks in line with the railroad wheel treads at the front and rear of the trailers. I use burnt umber for this kind of road grime and I simply drybrush it on. Then there's the tractor exhaust stains to paint on the leading corner(s) of the trailers, but that should be random since no two tractors are alike. Don't forget the "bow wave" effect on some trailers, either, since it helps show that they do spend some time on the roads and not just on the rails.
You'll also need to paint the roofs of these trailers silver. I lined all mine up and positioned them so close together they touched. Then I sprayed silver from the airbrush. This way I didn't have to mask any of them and it turned out great. I sanded each roof with 1000 grit paper before painting to give it some tooth since Bowser's paint came out so glossy I was afraid I might have issues with it adhering.
If you're not crazy yet, go ahead and paint the tail/running lamps with amber or red as appropriate. Then add air lines from the trailer body to the tandems. Then put some aged rust around the bumper and trailer door....
These are fine models. The real problem with them is how addictive they are.
Here's the page on my site I have dedicated to these trains:
http://www.geocities.com/norfolksouthernhinose/RCsCustomDiesels8.html