Hi Jack,
Thompson was the elder brother of my great great grandfather John Naisbitt (bap 10 Sep 1843 Rushen, IOM). I have found several other siblings - Parkin bap 22 Apr 1838, Isaac bap 31 Oct 1841, Bright bap 30 Nov 1845, Margaret bap 8 Oct 1848 and another Isaac bap 22 Oct 1854. Cuthbert was born in Appleby, son of Cuthbert Naisbitt and Margaret Thompson, I believe. Jane Parkin was from Torpenhow, though I have not yet found her baptism record. The family seem to have moved from Appleby to Isle of Man, then to Durham where they eventually settled, after following jobs around the coalfields.