that would be what a PF 54 is, a diminished proof. Personally, I think that's waaay off base. It appears to be your average 1960 Proof Washington. Maybe a PF-65 or so. there also appears to be a dark brown toning spot ( a tiny dot) at 7 o'clock on the obverse.
All in all, it's a nice coin. Not the 1804 dollar, but it's a nice proof washer.