I know you guys immediately determined it to be a scratch, so I've uploaded a few more pics, so keep an open mind. It's not a scratch. Judge what you see in the pics, no need for unpleasantries. Thanks.
If it was struck through (a string) how do you explain the parallel curved line running right below what you say is a string? In your first group of photos it's prominent on the bottom 2 pics and in your 2nd set the line is clearly seen on the top pics.
With the crappy Zincolns made today, anything's possible. Though I just cant see a piece of clear tape making an arc like that.