there are numerous refs to Alexander Bonnyman/Bonniman on www.manxnotebook.com - eg see www.manxnotebook.com/famhist/families/radcliff.htm - Jane was niece of his first wife - Alexander was trustee of 1st Congregational chapel in Atholl St Douglas so this might make tracing him in church records somewhat difficult - all records state came from Banff - he even named his residence Banff place - The Atholl's were well known for nepotism so I suspect his family would be well known to the Duke.

The Atholl papers are a large collection of letters etc relating to the Atholl involvement as Lords of Man to 1765 + as governor to 1828 + owner of large amounts of land - they may well give some details but at present need personal search at Manx Museum