Everything "870" that I have had Rose Action Sports do for me was done very competently. I never had anything refinished there, so I don't know what Steve offers in that regard.
My sole remaining 870P is from the era of Remington's "troubles," but by the time I got everything hashed out it was every bit as functional and reliable as the old ones. It took time and some patience to get there, but looking back, that was when I had plenty of both to spend on such a project.