I don't see any connection between the two Gelling lines.
Elizabeth Gelling b 1882 Malew was d/o Richard G & Ann Cain. Richard b 1849 Santon s/o Edward G & Isabella Gilmour. Edward was b 1826 Marown s/o Richard G & Elizabeth Cannell. Richard was b 1795 Santon s/o Michael G & his first wife Margaret Clague. There is no baptism record or other reference for Michael Gelling, so the line stops there.
The other line is a Braddan line from Ballacottier that goes back to John Gelling (abt 1744-1833) & Isabel Craine. I haven't found parents for John, though a possibility is William Gelling & Isabella Craine of Ballaclybane Braddan, and that line can be traced back a few more generations. Brian Lawson was connected to them.