Here is a HO unit I just did, a new Bachmann RS-3 in the Boston and Maine. The Bachmann unit comes nicely painted and detailed, but it lacks a lot of details, mainly that it has no end grab irons. I wanted it to look as close as possible to the Boston and Maine prototype, so I also added a lot of other details.
Looking at a lot of photos, showed a lot of variation, but I think I got it pretty close. The things I added were the end grab irons, cabinet equipment box, pilot beams, mu hoses, pilot grabs, roof grabs on the ends, steam intake and exhaust stack, marker lamps and lenses, windshield wipers, and roof lift rings. One thing I found is that of the detail parts available for the RS by manufacturers like Cal West and Custom Finishing, none were correct for this model. For the end grab irons, I did find some conventional ones that were the right size, so I bent them to give them the curves they needed to wrap around the shell. I used Google Sketchup to create a template for the hole locations. Fortunately, I was able to add these grab irons to the shell with only some minor damage to the maroon paint. For the lift rings and end roof grabs, I made them by bending wire around a fine tip pliers. For the steam intake and exhaust, I made them from styrene strip bits. With the black roof, it was fairly easy to blend in these parts.
I also removed the stock Bachmann horn, and replaced it with a Cal Scale M3-RT1. I modified the horn a bit, made the necessary bracket and attached it to the cab. I also painted the exhaust stack silver, and painted other areas that needed yel