Hi Angela
I'm not getting any great leads I'm afraid.
Michael Junior's age is the main stumbling block.
In 1901 he says that he was 33 giving him an approx birth year of 1867.
Given that our civil registration began in 1864 it's a tight timeline ~ It was nearly 1900 before it was common everyday practice.
It's also possible that he was older ie born pre 1864 which means we wouldn't get a birth cert at all.
I know he says that he was younger on the 1911 Census but I'm more inclined to go by an earlier census (when we are younger our memory is better
).
Land Steward for his father's occupation I thought would through up some good leads but nothing so far.
It's possible that this may have only been his occupation for a while, he could have been a farmer too.
Land Stewards sometimes move with their landlord to other areas that needed attention so again another possible stumbling block.
One thing I noticed was that you were discounting a family based on that you would have imagined that Michael Senior was still alive in 1901.
Michael Junior was born in and around 1867 ~ it's possible that his father could have died the following year ~ who knows ?
Also, with country Irish families you need to, in general, work on the men being a bit older than their wives. Not a hard rule but a general guide.
The County Men I have found to be more in their late 30's early 40's when getting married to a late teen / early twenties girl.
Also, Michael Junior could have been the youngest of the family which pushes our timeline back much further.
Sorry not to have any great leads for you but I'm just trying to explain why you may be finding it so hard to find records.
If I come across anything I shall let you know !
Tara