Hi,
Mention of the Canadian Custs brought the following to mind.
From the Londonderry Sentinal of 5 Nov 1858. " on the 7th ult at Peterboro', Canada West, Mossom Boyd Esq. son of the late Captain Gardner Boyd and nephew of Lt. Gen. Boyd H.E.I.C.S. to Letitia Magee, only daughter of the late Henry Cust Esq. Magilligan and niece of Major Gen. Blackall, Bengal Army."
On 17 May 1808 Henry Cust had married Mary Blackall in Magilligan Church of Ireland.
Regards