The newspaper items are from the British Newspaper Archives, available directly from BNA or via FindMyPast (for some subscriptions).
I assume John was the husband of Mary (nee Dunn), and that she died in 1940 and was buried in Amble West Cemetery.
FindAGrave appears to have good coverage for the
cemetery but no records for Mary. It's possible she may have a memorial stone that just hasn't yet been photographed, and if so, it might possibly have a reference to John. It's a long shot, I know.
Do you know if any of their children married around 1930? I'm wondering if any marriage record indicates whether he had died or not, at the time of the marriage, as it may help narrow down the time period of a death record.
GRO reference:
1940 Q4 Death: Mary Douglass; age 76 (born c1864); Northumberland North Second; 10B; 798
Newcastle Evening Chronicle
01 Oct 1940
Deaths
Douglass
- Amble, 3, Newburgh Street,
- on the 30th September,
- aged 76 years,
- Mary, beloved wife of the late John Douglass
- internment Amble West Cemetery, on Thursday;
- leaving residence at 2.45 pm for
- service in Church of the Sacred Heart
- where friends please meet. RIP