This is a Grenada OHMS Cover.  It was sent to Bath, England on 5/16/1893.

What makes this cover interesting is the OFFICIAL PAID HANDSTAMP in Black.  Above it is a cutout of a similar marking, though this one is dated 11/11/1897.  Included with this lot is a copy of a 1972 article in the British Caribbean Philatelic Journal by W. Danforth Walker.

This item is over $100 USD so I will ship it using priority mail in the states and registered mail overseas.  Both include tracking information and ensure that the item arrives in a safe and timely manner.