Any info on Mathew Diamond and Agnes Kirkpatrick first child born 1815 Dumfries

[BevStimpson]

my biggest brick wall.

Matthew (also Mathew) Diamond and Agnes Kirkpatrick have nine children that I can find as follows:

Matthew Diamond 1815 –
Joseph Diamond 1817 –
Mary Anne Diamond 1819 – 1858 (my Gt Gt Gt Grandmother)
Jean Diamond 1822 –
John Diamond 1824 –
Elizabeth Diamond 1830 – 1912
William Laidlaw Diamond 1832 – 1919
Margaret Diamond 1835 –
Agnes Diamond 1837 –

Matthew died in 1849 in Carlisle, he was a hand loom weaver. The youngest child Agnes is the only one born in Carlisle not Dumfries. The only census I can obviously find him on is 1841. Agnes (Kirkpatrick) lived to the ripe old age of 98 years.

Both give place of birth as Scotland, Agnes even mentions Dunnaford on the 1871 census.
I can't find a birth/baptism for Matthew, nor even siblings. I found two for Agnes, both the same year, difficult to decide which is which. But I cannot find a marriage anywhere for them. The age given on the 1841 census says both were 45 years old.  Which fits with the ages on all the other census returns for Agnes. And gives a birth year of circa 1782.

What am I missing? I feel as though I have the information I need to find Matthew and his parents, and sort out Agnes parents, plus the marriage, but somehow it is eluding me.

Any ideas to break down this wall will be greatly appreciated.
Beverley