try www.manxnotebook.com/famhist/genealgy/emig.htm for some discussion of emigration,
www.manxnotebook.com/famhist/genealgy/imig.htm for some discussion of immigration -
www.manxnotebook.com/famhist/genealgy/england.htm for some discussion of emigration into England.

Your period extends across the 1765 watershed - prior to this date many Irish merchants in Douglas/Peel involved with Running trade (likewise Scots in Ramsey) - post 1765 most removed and there are many reports of Manx emigration - Irish came back to Island during Irish troubles - likewise in 1840's economic migrants tho many of these were quickly deported back to Ireland.