What to do now?

I recently spent quite a lot of money on an older slabbed MS 62 from 1834. A great coin with though with a bit of a darker patina than might be in vogue now.

About over night, I noticed three small dark smudges on the reverse side of the holder. The coin looks just the same as always. The darkness looks like it would if there had been three little pieces of scotch tape on the slab, but it is within the slab.

Then below there are some smudges in the plastiic that look like they could be wiped off but cannot. In fact, I tried to wipe the smudges off and a bit of the silver hologram label, a little corner, wore off! I did not know that could happen.

Is the slab going bad? I had thought part of the value of the coin was the older slab.

Of course the coin is not at risk over night, but this could get worse. And how would NGC view this? Do they reslab without regrading?

I know they have said they do not crossover if the grade would be lower, but this is different.

I would not want to risk losing the MS-62. I think they like more lustrous coins now.

Very weird. I look at my coins often and handle the slabs often, but take superb care of them. No one else handles them.

I would be sorry to give up the old slab. Thoughts from veterans? I do not have an image of this. Thanks much!

Also, what are thoughts on registerd mail vs. overnight insured?