as you say - not accurate enough yet I suppose. Mind you I would go to Mayo for any reason

The census looks very much like
Ballyhouness (an 'h' rather than a 'w') which I am confident could be heard or interpreted as Ballyhaunis but there is always a doubt. It does border North galway and Roscommon. My sister's in laws came from 'Ballyhaunis' but records were Roscommon.
I think I saw that the Connollys show Kilmaine, Mayo on one census?? But that is in another direction according to the map.
Do you have his marriage details for his father's name - that may help eventually.
best wishes
heywood