Hi
Have a bit more for you to "digest".

If I'm recalling correctly, I think you also said that you had dismissed the record of a
Martin STEWART baptised 1840 at Doon. ??
I checked this at FindMyPast and it says >
"3 February 1840
Martin .. s/o J .. orge ? [with a question mark on the transcribed version] STEWART and Biddy MOLONY ... of [can't decipher name ]
.... Nancy and Thomas MOLONY .. [who are probably the sponsors ?]
Parish : Doon and Castletown
County : Limerick and Tipperary".
------
There is also a "tree" at the ancestry website for this same Martin (the record had been written up for a "Martin George "Mtn" STEWART (1840-1918) -- Doon RC Parish records :
Parents: George STEWART (1810- 1881) and Bridget MOLONY (1820 --)

A "Nellie MASON" is recorded as the first wife of "Martin George STEWART".

Further - there is an enlistment record for the year 1858 - Royal Irish Constabulary - Martin STEWART - 19 years - born Limerick :
[I think the date of service ended at 1864 with a note that the man STEWART was departing for Australia. ]

Will leave it for you to decide.

~ Lu