I'm finishing up on my Olympus Wide-S. One thing I notced is a sharp 'burr' on the film rail. I am worried that the film will get scratched. What is the best way to smooth it out?
A kitchen knife would be my first go-to tool. Keep in mind that the film's imaging area shouldn't be in the film rail path, that's just where the sprocket hole part of the film runs. You might want to ck the black, flat areas on either side of the film chamber opening for any nicks, as that is in the film image area, but they're probably fine.
^ this. Sand it off carefully and tape/block off the other parts so you don't get debris spread around. Take a look at a test roll of film being pulled over it and see if it even effects the sprockets. Id sand it off just in case any little bits of film get scraped off into the camera which has a tiny but possible chance to jam it over time.