Am I right that David died before the 1841 Census?
I can see Susanna and children in Clifton, Glous in 1841
Do you have this Baptism?
DAVID MOFFAT Gray 10 Jun 1821, Parish Church, Kinghorn, Fife
Parents David/Susan nee Flockart
Death Regs;
GRAY, DAVID age 56
GRO Reference: 1840 S Quarter in THE CLIFTON UNION Volume 11 Page 223
So born c 1784**
GRAY, SUSAN age 45
GRO Reference: 1846 J Quarter in BRISTOL Volume 11 Page 113
(c 1801)
I see they Bapt children Glous 1823/1834
As David is not on the 1841 Census it is hard to know where he was born.