My grade would be Poor-1. You can barely make out the date, and the obverse is almost all gone. Unfortunately the corrosion spot on the obverse take out of the class of very low grade coins that could get into a straight grade PCGS holder.
Believe or not there are now collectors who collect "the poorest known" examples of the PR-01 coins. There is even a registry for them. It's not my thing, but it is for others. Getting coins into those very low ball straight grade holders is hard. All of the wear has to be natural, and there can be no big scratches, dings or environmental damage spots.