Hi Haymur,a long shot but with Joseph being from Dublin there's a strong possibility the Royal Dublin Fusilier's may have been his Regiment might be worth checking any VC winner's from that regiment as a
starting point,that said looking at the medal roll index there were an awful lot of Joseph Byrne's in the
regiment,there does seem a good few in Ancestry's service record's that have survived sadly I'm not a
full member so no access but I'm sure someone will be along soon that might help any information ie
address,wife etc would be a great help.