Barry, the mother appears to be Margaret Henry (could be Hendry)--I haven't been able to find out her origins though censuses say she was b in Lonan.
The IGI re: marriage of John and Agnes indicates his middle name is Dominque. He wasn't ch with this full name however so not sure which of the many John Gellings he is. Farther back Sophia LaMothe md James Gelling and they had a son John Dominque Gelling ch 1806 German,named for her father Dominque LaMothe. I suspect your John Gelling somehow ties into those folks but I haven't discovered the link as yet.
You mention Quilleash--where does that name come in?
Donna