Too often we think we need to buy the most prototypical models available. In general, I do agree, but for some project, using more generic model is a matter of time or money. In my case, I'm working from old Roundhouse cars. In the past, I changed the running board, stirrups and grab irons. This is a very fun but time consuming process. It also makes the cars a little bit more fragile, which is not a good thing for this particular model.
This time, I've used stock models. I didn't upgrade them. However, I decided to carefully weather them using several technics and layers to get a prototypical result. All cars were weathered according to prototype pictures. Lance Mindheim often like to remind us the choice of colors is one of the most crucial part of a layout. I do agree with him and it's why I think weathered cars are much more important than prototypical ones.
You will see that I didn't include any rust spots and rust streaking. This technic is too often overdone and doesn't fit old time cars which were never left to degenerate into rust buckets.
Here's the result after a very busy day changing plastic shells into realistic weathered steel cars.