Remember that the mint was still applying the mint marks to the dies by hand in 1971. The location, depth and alignment could vary by the obverse die used to strike the coins. Even die polishing would change the look of the mint mark and other features on the resulting coins. Your coin looks like it was struck by a different die than your example.
"Shine, shine, a Roosevelt dime
All the way to Baltimore and running out of time" - Tom Waits 'Clap Hands'