Hello
Are you sure you have the correct 'Muff' ?
Muff ( Irish for plain) is a common place name in Ireland, it is more likely that the Muff in question is the townland in the parish of Lissan, County Londonderry. The marriage of Mary Jane Jordon and Robert Bell took place at Cookstown, the church record states in the parish of Lissan.
James Jordon is recorded in the townland of Muff, parish of Lissan in Griffith Valuation, 1857
On another point I see an online tree on ancestry where James Jordon's wife is called Annie/Nancy Gurley.