While I'm certainly not a rivet counter in terms of lettering, I still consider a car should reflect its era and while I've seen many people use post-1990 white-colored CN covered hoppers for gray-colored hoppers, it's certainly not a path I want to thread.
Colors and shapes are the most recognizeable aspect of an object (given we can't reproduce smell in a practicaway). Failing to graps these fundamental characteristics won't pay off if your goal is to reproduce something.
A few years ago, I made the mistake to buy CN Procor hoppers in the wrong color. More than once I thought about selling or swapping them for correct ones, but as high quality car prices raise, repainting them quickly became a practical option.
But at the same time, being practical has a lot of advantages. Instead of completely disassembling, stripping paint and repainting my fleet of white Procor cars, I've decided to erase the lettering. My technic is simple and only require fine sandpaper and Solvaset. This particular product is generally strong enough to soften pad printed lettering. In case of small letters, they disappear in a matter of a few seconds while large logo like the CN noodle can take more time and care. To prepare this model, it took me about 90 minutes, which may seem long but is a fraction of taking the longer route.
When lettering was completely removed, I repaired and glued back loosen parts, wiped the model clean with 70% alcohol and misted a light coat of white primer to give some tooth for the new coat of paint. As for decals, high quality Highball products will be used. Two others to go!