There isn't really enough information to pin this Michael down. There are five 1940 marriages that are plain Michael and one Michael J. Three SQ and three DQ.
I had a look at the Irish marriages of which there appeared to be only four. None of them had an occupation of miner and, apart from one whose age was 58, all were stated to be of full age. Michael would be about 27 in 1940.
There is a Michael Reilly in the 1939 and his birth date is one day out, otherwise the month and year are the same as on the death record. He is in Birmingham.
Phantom - do you know the name of his wife at all?