I ordered a set of maple rings off Reverb, they arrived today, so points for getting here promptly.
One thing I was not expecting was for them to be unfinished. There's also some tear out around the pickup adjustment screw holes.
So I guess I have some sanding and finishing in my future. Unfinished, maple is pretty much guaranteed to move over time, which is going to be fatal for something as delicate as these. Rosewood and other oily varieties are probably ok.
Looking closely at the competing Tone Ninja (Germans have the worst branding) ones, looks like they may be even rougher, and do not even sport the recess holes, so that's a couple of points for Guilford.