I've had an ongoing interest in Black Loyalists and Black Maritime history since my days at Acadia University. (I did a thesis on leaders of the black Baptist Church in its 1st fifty years of existence in Nova Scotia.) I have recently been doing a lot of research around those Black Loyalists who sailed for Sierra Leone. No doubt you have already read over the Book of Negroes (which lists all blacks leaving the USA in 1783) at the Black Loyalist Heritage Society of Nova Scotia's website. Robin Winks' two books on aspects of Black Canadian history are also excellent. Contact me if you think I might be of help.