Here are the transcriptions in the Quermore Methodist MI booklet at the library. Happily it does look like a good match for the family on the 1881:
Quernmore Methodist Chapel, Section B, Row 2
G6 "Henry Brown of Parbold, d. May 19th 1947 aged 77 years, also his wife Margaret died March 7th 1954 aged 80 years"
G7 "Margaret, widow of the late John Brown of Sunnyside, Dolphinholme, died March 3rd 1926 aged 91 years"
So Henry born c. 1870 and Margaret (widow of John) born c. 1835, which is what you wanted. However John Brown of Sunnyside does not appear to be in that cemetery, he is only mentioned as being Margaret's husband.
I couldn't see him in the listings for Quernmore C of E church, nor in the ones for Dolphinholme. There were these Browns in Dolphinholme St Marks churchyard (C of E) which I got in case they were of use:
Sec tion B, Row 5
G7 " David Brown died March 31st 1913 aged 91 years, also Ann his wife, died May 13th 1923, aged 78 years, also Joyce their daughter, died March 28th 1936 aged 56 years, also Mary Margaret their daughter, died june 29th 1960 aged 89 years."
G8 "David Brown died February 23rd 1960 aged 84 years, also Margaret his wife died July 19th 1960 aged 79 years"
Row 6
G8 "Henry Brown, husband, father and grandfather, died 5th December 2002 aged 81 years"
Advice of the librarian was to try the City Museum for info on Richard Brown and Crimea casualties before going through the neswpapers, in case someone else has already done it.
If that doesn't work I'll book a slot on the film readers next week.
Barbara
(Not the same Threlfall family, as mine were still in North Meols in the early 19th C)