Didn't like my offer so the coins are going back finally. Have a feeling I will be happier with that decision. Thanks for everyone's input in the thread!
If you have a headache over the coins now, that headache will only get bigger if you keep them. Sending them back was the right move, always aim to get problem free coins. If you must get them graded get them from the top two TPGs.
I think the hairlines you're seeing as cleaning are just bag marks from the coin bouncing off of other coins in the mint bags a long time ago.
Good decision sending them back though.