This has to be a possibility for James' baptism in the Ballymoney RC parish registers, April 10 (1864), James Beckett of Stewart [Beckett] and Bridgt McMullin, Sponsors Patrick McMullin and Margt McGuckian:https://registers.nli.ie/registers/vtls000633108#page/40/mode/1up (left page)
Lots of other children were baptised for parents with these names ... Stewart John in 1867 (Ballymoney and Derrykeighan parish).
in 1921 James is aged 60 born Ballymoney, Rachel aged 62 6 months born Autical,? Ireland