Dipping is always a gamble. But even when it works, if residue is left behind, it will become a future problem.
Those carbon spots are the result of pinholes in the mylar. It looks like a V29A based on that die chip on the obverse star.
Ironically, a dip might restore it. You'd want someone who knows what they're doing, someone experienced, someone like NCS. If it could be done to a coin, and pass as "conservation," they did it.
I agree that it should be professionally conserved. It is definitely an o/o, and a nice example of it--an average New Orleans strike in nice condition. I would send it off for slabbing and conservation--it is worth it.
These types of toning spots are caused by pinholes (Post#8). A proper dip will remove them. Unfortunately IMO, the deep black on the rim is beyond fixing by 95% of the coin collectors/dealers who would just dip the coin leaving a dull gray, corroded mark on the rim and the spot above the cap. 98% of the time, a raised black area on the coin (in this case there are three) indicates the underlying surface is etched. A professional, a coin doctor, and the folks who know about pretreating a coin before it is dipped (NCS specialists) could fix it; however, IMO not worth the price at NCS.
Dip it, rinse well, then it would make a good coin for a Dansco album. The black spots will leave scars, but not as bad as the spots themselves. Not worth spending money on having someone mess with it.
The o/o isn't all that common Who says it is AU? I think it is MS, with the typical New Orleans weaknesses.
I do... First, the 29a isn't a premium list VAM so the omm is irrelevant. Second, the luster is muted and it seems as though all the devices are weak. Not just the traditional highest point areas diagnostic of an O mint weak strike and third, the nail in the coffin that explains everything is that imo it's been polished or whizzed. That explains all the features I just listed plus look at every bag mark on both obverse and reverse. None have sharp edges or metal push. The rounded edges of all bag marks along with everything else I just mentioned plus the overall look tells me it's been whizzed. Almost no doubt a good light whizzing but polished nonetheless imo.
I don't see any sign of it being whizzed. It probably was dipped before, and has retoned in an unattractive manner. I see a typical MS New Orleans mint Morgan, and the o/o does sell at a premium. As regards luster, it is impossible to judge that from those photographs at an angle.
Your latest photos hint that there is original cartwheel lustre on the obverse but the reverse still appears to have been over-dipped.