I note the marriage of Matilda junior and the likely death of Emma.
Marriages Sep 1849
Evans John Stourbridge 18 530
Evans Matilda Mangion
EVANS, EMMA 1
GRO Reference: 1840 D Quarter in STOURBRIDGE UNION Volume 18 Page 316
I guess these are the deaths of Matilda & her daughter Matilda.
Deaths Sep 1884
EVANS Matilda 84 Stourbridge 6c 121
Deaths Mar 1906
Evans Matilda 28 Stourbridge 6c 77
The 1841 census was rounded down to nearest 5, so John could have been 44, so born 1797-1800, there are 18 baptisms on freereg for a John, none Kingswinford, but below nearby.
John EVANS Baptism 08 May 1796 Staffordshire Brierley Hill : St Michael : Other Transcript
Possible deaths below.
EVANS, JOHN 58
GRO Reference: 1855 M Quarter in STOURBRIDGE Volume 06C Page 127
EVANS, JOHN 64
GRO Reference: 1864 M Quarter in STOURBRIDGE Volume 06C Page 125
No baptism of John Bernard Mangin Evans on family search, no records are on freereg for Bridgnorth.
No marriage for John & Matilda, the record may not have survived, or it may have been a civil marriage and not recorded or maybe they never married?
I did see on family search the mother of Matilda was Susanna, no father noted.
Colin
Colin, thank you :-)
To enlarge the known details (and assist the search) I add this:
1. On Ancestry there is a Thomas EVANS bapt. 5 Jan 1823 Brierley Hill to a John EVANS + Matilda. [Baby Thomas died 27 May 1824]. This adds weight to your suggestion of John EVANS [bapt 1796?] coming from Brierley Hilll, since the pairing of a John Evans + a Matilda isn't common.
2. Matilda Mangin Dalley was illegitimate, yes: the Bridgnorth register says 'base-born', and her unmarried mother Susanna Dalley had at least 2 other later children presumably with different fathers. The MANGIN (very unusual in 19th century Shropshire, it seems to be Irish) ought to be Matilda's father's name? It doesn't occur in the Dalley family backwards; I've searched hard.
3. You think it's possible that John EVANS and Matilda Mangin Dalley didn't get married. I do too. Matilda's mother didn't marry but nevertheless had children. Family tradition?
4. This leaves us with the challenge of "John Bernard Mangin Evans" born approx. 1826 - which is what I actually want to solve. You can't see any baptism, Colin, nothing showing anywhere. I've drawn a blank, too, when looking for the name that's given on the 1841 census.
So: new thoughts.
If John EVANS and Matilda Mangin DALLEY weren't married, it could have been a fairly loose relationship... therefore could JBME be a son of just Matilda's, born in between Thomas Evans 1823 and Matilda Mangin Evans 1826, with a different father (not John EVANS?)
Could this man JBME be 'John' + 'Bernard [the father's surname?]' + 'Mangin [= Matilda's father's name?]' + EVANS (to bring him into the family unit, because Matilda is living with John Evans?)
I know this sounds complex, but I've often found that people's middle names give the clue to their blood-line. And there are 2 middle names here, more than is strictly necessary! so they surely carry some importance, if only we could recognise it.

D x