This is a PCGS certified piece I bought about five years ago to complete my date / mint mark set of mercury dimes (I had been chasing the set for 25 years!). Let's hear your guesses!
G-6. It's got too much rim to get a G4 -- from what I've seen in pictures, G4 on the 1916-D seems to be reserved for coins that would be called AG03 in any other date.
G4. I have one just like it in a PCGS holder, with this grade. I would probably have graded it G/AG when I was a kid. My, how things have changed.