MS62 BN I think the coin will grade straight. I have seen similar stains on graded zinc cents. Amazing variety one of my many faviorates, I never got the one I found slabbed as I like to study it in the raw. Imagine, 12 different dies and still a very low pop? I read were the opinion is a deliberate concentrated effort was made to destroy these coins after die trials, also read the mints just needed extra dies at year end? I go with the first as many more would have been found like the 2000 RDV-006. Mentioning that even the lowly 1998 and 2000 are a blast to find, searched about 1 and a quarter million cents and found 3 2000 and one 1998
WAM. To me anyways that's scarce. One 1988 D RDV-006 out of these I searched equals rare and dang lucky category.