Unknown Father

My Husband has an unknown father, I received a Ist cousin match on My Heritage 818.6cm, we got in contact with each other and we don't have any common ancestors that we recognise with each other. The first cousins father and uncle are too young to be a father for my husband. He father has too half siblings, as his Grandmother married twice, the point is I'm trying to work out who my husbands Grandparents are, so I can nail down who his father might be?

Smiley2770