Questions About Unusual Markings/Brandings On Barber Coin

Hello! I will keep this part brief, but if you want to skip to the good part just scroll to find **** because that's where the questions start.

Basically I'm a college student of 20 years, and have recently been watching a lot of shows such as Storage Wars, Pawn Stars (not my favorite) American Pickers, and so on.

Mind you, I know the vast majority of these shows aren't good examples of reality, but I like to think it prepared me for what occurred today.

You see, my 92 year old grandmother needed help cleaning her closet and moving her winter clothes to her summer clothes. I volunteered and we found an iron box with a few old papers and a small box that contained inside a ton of old coins. I jumped for joy and promptly started researching their values.

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I found three silver half dollar Barber coins, two minted in D and one with no mint mark meaning P. Their dates were 1906, 1907, and 1908 respectively.

This 1908 half dollar barber coin has a D printed on it and is in good condition, but it was different from the other two.

You see.. there are markings on the neck and in the crest of the eagle.

These markings are indentations on the coin and to my untrained eye and super large biology microscope, consistent with the other wear-and-tear the coin has been through. For example there's a scuff mark that overlaps both the normal coin and these unusual markings.

On the 'heads' side below the chin at the base of the neck but above the date there are three letters. They appear to spell out L or perhaps an I, a dollar sign ($) with two lines going through it, and a N or maybe a V.

On the crest of the eagle on the 'tails' side there is what looks to be a flipped micro (mew) sign underneath a wide V with a loop connecting the two and the number '36' resting between the V but on top of the micro sign.

I'm really not sure what this is, but google results have given me no answers so I turn to you all for assistance. I am attempting to take photos and will upload them soon.

Any idea what this means? Is it an error, or a rare mint thing? Is it a fake?

Thanks for any advice you can give me! Even if its 'this coin is a fake' or 'its worth nothing because someone tampered with it,' I just want to know the truth ^^.