All I know about John Evans is from the 1915 marriage certificate-
he was 24 and his father was Edward Evans (deceased).
John Evanss was living at the same address as Grace and her parents and several siblings when they married in 1915 so he may well have just been the lodger!
When Grace later married Graham Cowles in 1934- in High wycombe- she gave her address as Winton, Bournemouth- and declared herself a spinster- but had she been widowed by then or did she just leave her first husband John Evans?
At the moment I feel this last question of tracking John Evans after the birth of John Cowles vans in 1916 almost impossible as I cannot think of any way to find out any definitive information.
when John and Grace married in 1915, the 2 witnesses were Grace's parents so John was clearly away from close family. His job is shown as a motor engineer- a very similar employment to Graham Cowles who Grace later married!
I wonder now what happened to John Evans who married Grace Rainer in 1915
By any chance was there an occupation listed for John's father Edward on m/c?
Have you checked the 1911 census or 1939 register to see if there are any persons named John Evans born c1891 occ motor engineer?
I have found these two records for a John Evan's born c1892 father named Edward........but neither have occ motor engineer
John Evans Age: 3
Birth
7 Sep 1893Admission Date: 12 Jul 1897
School: Mina Road School
Father:
Edward Evans, address
3 Domville GroveThis family are together at that address 1901/1911 John porter
1901 Piece: 520 Folio: 42 Page Number: 10
3 Domville GroveEdward Evans 46
Emma Evans 45
Edward Evans 15
Ernest Evans 13
Percy Evans 11
May Evans 9
John Evans 4 Surrey (1911c still with parents occ porter)
John EVANS
mmn UNDERWOODGRO Reference: 1893 D Quarter in ST SAVIOUR LONDON Volume 01D Page 27
Edward Evans married Emma Elizabeth Julia UNDERWOOD 22 Fe 1885 All Saints Walworth Southwark,
it looks as if Edward died 13 Nov 1931 Burial Cremation Southwark
https://www.findagrave.com/memorial/218418694/edward-evansJohn Evans age 28, batchelor, labourer, 3 Domville Grove married
14 May 1922 at St Mark, Camberwell, Southwark father
Edward Evans, occ
painter & decoratorSpouse:
Edith Violet ThompsonJohn Evans Age: 6
Birth Date:
Feb 1892Admission Date: 1 Jul 1898
School: Maidstone Street School
Father:
Edward Evans, address
19 Warburton Sq.GRO indexes have a lot of births for a John Evans born Mar qtr., here are two that were registered in London area and details for John mmn Baker
EVANS, JOHN
mmn BAKERGRO Reference: 1892 M Quarter in SHOREDITCH Volume 01C Page 90
EVANS, JOHN
mmn ALLENGRO Reference: 1892 M Quarter in ST SAVIOUR LONDON Volume 01D Page 7
Edward Evans, minor, occ scale maker married
24 Dec 1882 at St John, Hoxton, Hackney Father: Edward Evans, coach maker
Spouse:
Ellen BAKER1901 Piece: 224 Folio: 86 Page Number: 23
19 Warburton Sq.Edward Evans 38
Ellen Evans 38
Edward Evans 19
James Evans 10
John Evans 8 Shoreditch (1911c with family same address occ scale maker)
Rose Evans 6
George Evans 4
Arthur Evans 2
John Evans age 22, scale maker married on
25 Dec 1914 at St John, Hoxton, Hackney
Father: Edward Evans, scale maker
Spouse:
Annie Alice Rosina Bigwood