I will add that there are only two major rarities of the Jubilee head silver series: 1893 6d which in mint state is one of the rarest 19th C. business strike rarities 1889 Small Head Shilling in mint state I will add that this one is in hand truly exceptional and will tip hand in that it is "top pop" for both NGC and PCGS combined pops...
MS64 sounds about right. The black spot at 12 o’clock on the obverse is distracting, and this is an original looking coin but a little mottled and splotchy for my taste.
Guessing 66. I've handled a 65 of this date and they're much nicer than pictures tend to make them look, especially with light toning.