I bet that marriage is theirs. I don't know much about mixed denomination marriages and whether he would HAVE to be baptised before the event. As I said, that church was probably only across the river and she may have come from that Parish.
As for the will, they are supposed to be coming online soon, but I have had wills photocopied by PRONI and posted to me. I sent a request on their Contact email address and asked them to send me an invoice. They did that, with a reference number on it, I sent them a cheque and bingo. Maybe someone on this site knows when the wills are coming online. You should be able to find them on the 1901 census if we can find their address in that year. Onwards. RosemaryJoan