Morning vs. Murnane
The common spelling of this name is MURNANE.I'm wondering if perhaps some of your ancestors spelled it this way which might account for any brick walls.
My MORNINs always used that spelling in Ireland.In America it also became MORNING and MARNIN.
There is a special MURNANE site online which can be found by entering the name is a search engine.Lots of message with many names and dates.
Just a suggestion.Gary Radcliffe, West Covina, CA