Hi Joe.
Thomas wasn't on his own in 1861 - with him at no 46 were his wife Margaret and two sons from his first marriage, his son Archibald from the marriage to Margaret, his brother William (another tailor, probably one of the men Thomas was employing) and a lodger (a tailor, so the other employed man). Son William would have been one of the two boys employed as he was an apprentice tailor.
I eventually found Thomas in hospital in Paisley in 1871, which was why he wasn't at home then, and he subsequently died in Glasgow in 1874. As the death was due to 'sudden intemperence' (!), I have no idea what he was in hospital for. Margaret, his widow, was living in Barony by 1881, so it seems fairly likely that the family had all moved there between 1871 and Thomas' death in 1874, especially as the death was reported by his son, Archibald, who would only have been about 15 at the time.
Regards,
Manui