I'm trying to estimate grades on my better quality 1959/1960 pennies (over 150 in MS grades 63 to possibly 67. Almost all of the them are well-struck and bright red. 20+ are nearly flawless when it comes to scratches/dents, but they have a few to several to many small/medium/large dark (carbon?) spots. I haven't seen
many grade examples with these so I'm not sure how to factor them in to come up with a ballpark grade. My assumption is that the number and size are treated as "flaws." I have attached three examples--unfortunately, the spots are not as visible in the photos as under the loop. The 3rd example rev has a few more visible than the others. Some advice please?