Thank you vronlady and others for this. I am sure I have come across this Anthony Wilson at some point (probably through Slaters 1846). It is quite possible he is related to the Nicholas Wilson line. One Nicholas (I believe my gggrandfather) married a Louisa Hendy in Baltinglass in 1862, so they were in the same area around the same time.
Unfortunately I am away from most of my records for the next few weeks, but from what I have learned the Nicholas Wilsons seem to have been farmers in the area from Baltinglass to Hacketstown, although one record from Griffiths shows a Nicholas Wilson as a landlord. Some records can also be found in Carlow.