Hi staffee, and welcome to Outdoorking.
The reel is not perfectly matched to the bedknife. Possibly there is a slight curve in the bedknife. Whether that is cause for action is less clear however: it depends how much clearance there is in the center. If you have the reel perfectly adjusted, with no metal to metal contact anywhere, how much of the width is cutting the paper? If it is cutting for most of the width, I think everyone but the true perfectionists would try it on some grass, and probably be awestruck by how well it cuts. For the remaining 0.73% of reel enthusiasts who insist on perfection, I think the answer would be backlapping rather than a regrind. However it is all about how much of the width is not cutting the paper, and how sharp the leading edges of the blades and the bedknife are. You can inspect that visually and by the finger cutting trick.
Please let us know how sharp it is, and what percentage of the width is cutting the paper, then we can talk about what action, if any, is appropriate. Incidentally a couple of pictures would be great: seeing the mower, and the way it cuts the paper, would get us all thinking in the same terms.
