Wrong planchette? I don’t think so. Thin planchette is likely. Thin planchettes were more common then than they are now. Quality control, including that for the copper alloy, was frequently put aside for the sake of cost and efficiency.
I know that only a micrometer will work but I just put two 35 Lincolns next to it and took a level photo. It looks taller than the other two.
It is the middle coin.
Who knows.
The coin has the appearance that it was subjected to some type of corrosive. It could have been intentional or accidental, who knows! I believe that what you see as a Die Crack from Lincoln's nose to the rim, is actually a lamination crack. Remember, a Die crack will show up as raised on a coin's surfaces (fields, images, lettering, Date and any Mint Mark). A lamination crack will be level with the surfaces or below the surface unless the lamination peels and begins to separate or fold over. The piece making the "5" in the Date appear almost like a "6", is a Die Chip.