Had more to add but had to deal with something offline. In addition to what heywood has added- the 1917 Pension applicant was not only found in the 1851 census but was 80 years old or older in 1917 (otherwise it would have been noted on the form that he wasn't found).
Is this what you have.Baptism of Martin - 6th November 1855https://registers.nli.ie/registers/vtls000634611?locale=en#page/80/mode/1up