I wouldn't hold out much likelyhood of finding them in dublin unless you took the old ones in to a motor factors and asked their advice.
I've always found delivery from motorworks to be quick to Dublin.
your better off replacing the alternator or fully rebuilding it as the regulator and rectifier will be near the end of their working life. myles balfe in phibsborough may be able to rebuild it for you or source parts.
there are various auto electrcians about dublin ( golden pages )
I have a set of brushes if you want them.
Only use BMW brushes, if you use brushes you get from an Anto factor they will work but are a lot harder material than the original ones and will be a bit severe in the rotor.
I pm my mobile number.