Porgi, we have something in common, because my ancestors were also owners of The Three Tuns, on Sodhouse Bank, circa 1856 - 1886. On the 1871 census, Sodhouse Bank is referred to as Sheriff Hill, West Side, but the address is clear as The Three Tuns (Public House). My Grandmother was born (1895), just up 'the bank,' and I was born just off the top of the bank (1936).
There is a photo of the old Three Tuns in the Gateshead archives, showing a woman standing out front - has to be your, or my, GGgrandmother.
You can get a good 1895 Ordnance Survey Map of Sheriff Hill from
www.alangodfrey.co.uk which shows it as Sodhouse Bank.
Also suggest you read Catherine Cookson's book, "The Whip," which makes mention, several times about 'The Tuns' at Gateshead Fell.
Regards, Rob Hall, Katy, TEXAS