I got a carbide grinding bit for my Dremel today. I will give that a go and polish it out then check for cracks. I don't have any dye for finding the crack, but I likely can improvise with a Sharpie and a little more polishing. I also have one of those jewelers loupe things to get a better look.

I have two other cranksets on bikes. One has very few miles on it and the other one has seen lots of miles.

I am just glad I noticed it before disaster struck.