I googled "Jamaica and the slave trade" and came up with an item of interest from :

http://www.discoverjamaica.com/gleaner/discover/geography/history1.htm

"The second period of our history extends from.the destruction of Port Royal to the abolition of the slave trade in 1807. During this time Jamaica flourished as an agricultural colony and became very rich. It reached the height of its prosperity just before the slave trade was abolished; that is, just before the British Government decided that no more slaves were to be brought from Africa and sold as private property."

That Napoleon tried to set up a slave-trade and failed is interesting, and adds fuel to the intrigue fire.

All the commentary is very interesting. I'm reminded of Joseph Weller's Catch 22 with its wry look at the black market.

If any slaves were still coming out of Jamaica after 1807, it would involve some government official, or officials. Hypothetical English slavers, and French slavers, all "pirates" or "black marketeers" as need be. Lafitte's pirates "capture" the ships, and sell the slaves as mentioned. There is allegedly no record of captured ships.

What did those newly unemployed British slave merchants do when they'd been offcially given notice?

The West Indies was referred to back then by British gentlemen, IIRC, as "the white-man's hell." Certainly a temptation to grab all the gold you can, in that uncomfortable environment, in the hope that you will survive to return to England and enjoy your weath.

The West Indies was also generally loathed as an assignment in the British Army of the period, due to the low survival rate from all the pestilential diseases, yellow-fever, etc.

In war, there is chaos; in chaos, there is profit to be made. Whatever the "Big Picture" really is when sorted out, I'd expect to find plenty of intrigue.

Unfortunately Wise's work does not include any bibliography (though he mentions various books in footnotes, with regards to various points in history, beginning with Romans and Greeks and continuing up to about 1842), and his writing style is unusual. It would appear that he had completed much of the original work around 1939, the latest date mentioned in the text, but obviously would not get published until after WWII.

Thank you all for your responses, they help fill in the gaps, and the possibilities.

Regards, John