I received a coin from the Mint a few weeks back and noticed what I thought was a scratch. Looking at it from many angles it looked like a scratch on the rim that went down into the field of the coin. Well I finally pulled out the microscope today and upon further inspection it was a scratch, but on the plastic holder the coin rests in. I am just posting this because this scratch I was 100% certain it was on the coin from visual inspection, but in reality the coin was perfect and the holder wasn't. So all I can say is be careful on what you send back if it's a rare coin. A scratch may look real when it is in the plastic holder, but once it is examined further it may not have what it appears to have.
Same for almost any holder, especially the cellophanes. I will move the coin around a bit to see, but then you risk a bit of rub.