there may be hints in land records - I know from NSM Oct 1740 76 that he was brother-in-law to James Gell (ie brother to Elinor Gell als Kelly who d 1739 (will 1740) but whose marr I never found tho 1st child noted in Kk German in 1730 - neither did I find a bapt for her - her will has some v large claims - I would have expected a marriage contract if one or both parties came from wealthy backgrounds but can't find one

however there is a will for Wm Kell(e)y of Douglas 1735 - [Douglas]dated 31 Aug 1731;ch Elinor(w/o James Gell), John(dwelling houses); wife decd;servant Margt Cannell so you now have his father and I suspect his mother was Margt Murray m Braddan 16860826 + bur Bra 17130512 - there is a likely will episcopal 1714 but I don't seem to have a photo