Royal Munster Fusiliers 7048 and Royal Munster Fusiliers 35248 (2 service numbers against one entry)
On the evidence you have given us here, the balance of probability is that this is your man
The Munsters were as the name says a Munster regiment, and therefore one would expect a Cork man to join then.
I am not familiar with Munster service nos, you need to research those two, as to when he would have joined. Off the top of my head, it might appear that he joined before the war with the 7048 - in other words find out when that service no was allocated. Left the service, then rejoined around 1917, when the second number was given him
That in itself looks a bit odd, in that one would have expected him to be in reserves and called up early in the war if that was the case. He was getting on a bit in military terms, so could have spent the whole war with one of the Munster Reserve battalions which did not go overseas.
The medal card shows no 1914 or 1915 star so he did not serve in a war zone then, nor has he a SWB which would indicate that he was invalided out at any stage.
If it were me, I would buy the medal card entry (that is what the medal card index actually points too for the man, and get the battalion from that, which would confirm if he was in a reserve battalion.
The Munsters were fairly active in 1915 with battalions in France Gallipoli and Salonika. So if he was serving then one would have expected him to be in the trenches and getting a 1915 star.