Hi Marion
1. Yes, the census was a LONG shot

2. The occupations that you gave for Matthew certainly fit in with the Avoca area as there were copper mines there, so most likely that was where he worked.
3. Given the nature of the mining industry here at the time though it's VERY possible that Matthew was transient for work which means his marriage could have taken in another parish OR another county ( not all areas are covered on rootsireland)
4. Was there ever any suggestion that Matthew and Mary may also have emmigrated ?
5. For now I would just concentrate on the three girls whom you know for a fact had Mary McEwan (and variants) as their Mum ~ Doyle is WAY too common an Irish surname to presume that the other's were family too, don't discard them but as I say just concentrate on those that you are 100% sure of.
6. Can you tell me EXACTLY what variations of Matthew's wife Mary's maiden name that you have seen on AUSTRALIAN paperwork ?!
Tara