Not Expected Parent - dozens of matches

It is such a long time since I used the forum - mea culpa - if this question is in the wrong place, please put me right!
I and my mother Isabel Henrietta Sweeting 1919-2017 have more and more matches to 2 men called Cunningham, James Fairweather Cunningham b 1824 South Shields Co. Durham and his father John Cunningham born 1803 South Shields. I now have plenty of replies for DNA tested people and I have worked out a full family tree for my ancestor. My mother's closest matches are 199 cM x 9 segs, 94 cM x 6 both descended from James Fairweather C, 76 cM x 5 descended from John C,69 cM x 4 from John C and 58 cM x 5 from James Fairweather. I know how all these 5 and all the others, literally dozens, now relate to each other.

The problem is that I have assiduously collected GRO BMD certificates for my x times grandparents back to 1837, and followed PRs back from there to last 1/3 of c18th and there are no ancestors named Cunningham in my tree. This means that one of my ancestors is called by the name of her/his mother's husband, I assume. John Cunningham spent his life in South Shields but his son James Fairweather spent the years 1854 - 1867 in Deptford Kent. (births of children). There were no Cunningham witnesses at the marriages of his 3 of his daughters in S London between Febuary 1867 and 1870. By 1871 his wife and unmarried children were back in Co. Durham. James was working in the naval shipyards in Devenport, Devon
My mothers grandmothers were Henrietta Hurrion born December 1866 in Strood Kent ( 13.8 miles by road from Dartford. The Hurrions were frequently in Deptford on business, father named on B cert as William Ashdown Hurrion, who had a cart) and Margaret Jane Hepple (father named as Robert Hepple) born Sept 1869 in Howden,a suburb of Newcastle (apologies to Geordies if you find this offensive). James Fairweather C may have been on Tyneside in late 1868 but there is no evidence ; John Cunningham fathered his last known child in 1839, was living in Southwick Co. Durham in 1871 and died in 1873. My mother's great grandfather was Robert Mitchell Hepple born 1837 in Westoe, South Shields could have been fathered by John C but not James Fairweather C.
I have identified no Hurrion DNA matches from William Ashdown Hurrion died Dec 1870, or his siblings or aunts and uncles. I have many matches to his wife Henrietta Holloway (married in June 1870) who had a track record of illegitimate children before Williams'. I have many DNA matches to one of Henrietta's illegitimate sons, and 2 to the child born from her remarriage following William's death with DNA match to her son born 1873.
I have identified no Hepple matches from Robert Mitchel Hepple's father but some to his mother's Proudlock family, nor matches to Margaret Jane's brother. I have identified no matches to Margaret Jane's Turner mother, either.
Can you advise this blinded by science person as to how to identify which of her great grandmothers, or her 2 x great grandfather is the Cunningham cuckoo in her tree?

 

Oops... he died 1877! take as long as you like or need; I'm very grateful for another head looking at it.

 

Try saying Holloway in a NW Kentish accent! The Holloways were illiterate, poor earning money anyway they could (not always legally). I suspect their accent was very strong. There are several examples of their being called either Holloway or Oliver in various records I have come across. I too am inclined to think my cuckoo is Henrietta Hurrion but it isn't proof. And I am also short of Turner and Hepple matches, too. I can't think of a way to flush them out. I must have matches to 2 of these 3 families! I and my mother have tested with FTDNA, LivingDNA, MyHeritage and entered my raw data in Gedmatch.

 

If you have unexpected DNA matches because of an NPE you'll also have missing matches for the same reason.

 

Good morning, Peter, I'm glad you have joined in. And thank you, Helen for your thoughts.
I have Peter's "missing" ie no matches for Hepple father and Mitchell grandmother of Robert Mitchel Hepple and the Turner mother of Margaret Jane Hepple as well as no Hurrions.
MyHeritage has given me "cluster" groups which might help, but I have so far been able to identify a smallish number.

 

Shared matches with documented cousins are the best way to work out which part of our tree we should be looking in. Shared matches with genetic cousins are rarely helpful - you'll get clusters of matches but it's usually impossible to make sense of them. If endogamy is involved, and it often is, the common ancestor could be so far back that the match is essentially meaningless.

Note: I'm referring to the situation where your cousins are from an endogamous population but you aren't.

 

Sorry for disappearing but all communications from LC including the Forum have recently taken to being deleted by my laptop and I have to check "deleted" file to see if I've missed anything.I know Peter frequently alerts us to this as a possible problem in newsletters, but it has only been doing it for a couple of months and I'll have to wait till he tells us again how to prevent it.
I am particularly short of genetic cousins on my mother's side - the only child of a father who was an only child of one of 4 children, only 2 of whom had children and a mother who may have been the cuckoo. Her mother was the only child - illegitimate - of her mother who could be the cuckoo or the daughter of the cuckoo.
I'll go back again to earlier more prolific generations, where there are some, in public trees and check for matches again. And I'll take another look at the clusters, having noted your comments and good luck wishes, Helen.
I'll also look at the shared matches discussion.