Damaged serial numbers
Yes, I do have a USA Metal Slug 1 holographic label cart, but it is my only one and from my personal collection so I don't want to sell it!
However, I do also have an extra/spare really nice USA MS1 normal label cart that I can offer in trade to someone with a holographic?
Damaged serial numbers are not so bad, if the area of damage is limited to the center and middle of the cart sticker. Here is an example of how I cover them up nicely for carts in my collection.
Until I recently got a replacement, this was my personal Blazing Star MVS cartridge for many years. They don't look so bad my friend.