It's in Finglas unless you are trying to sell a house there.
and the houses are solid old builtEither way Beneavin is a grand area to live in.
I would be concerned if it is Finglas when Finglas hasnt exactly got the best reputation
If your concern is whether the area is nice to live in or not then it's irrelevant whether it is finglas or glasnevin. Being one or the other doesn't necessarily make a place good or bad, it's only an address and like you say addresses don't count for much since locations with the same address can be so mixed. So I think you are wrong focusing on the Finglas / Glasnevin question - basically it doesn't matter, it doesn't change what the road you want to buy on is like??
I would be concerned if it is Finglas when Finglas hasnt exactly got the best reputation
Glasnevin is in Dublin 9. Anything outside of D9 is not officially Glasnevin regardless of what the EAs say.