In the aftermath of WW2, Stone grew up in a working class household in Yorkshire County. He likely was raised in Sheffield, the largest city in Yorkshire and one heavily affected by the bombings of WW2 due to the presence of steel factories there.
Both of his parents worked jobs. After returning from serving as a British Army soldier in WW2, his father worked at a steel factory in Sheffield while his mother was a worker at a chemical plant.
Because of this, he was often left to his own devices as a child for some time during the day. Sometimes family friends or extended family looked after him while giving him a loose leash.
While Stone grew up as a “city boy”, he enjoyed the occasional visit to a farm belonging to an extended family member in the Yorkshire countryside. He got to run wild there and explore.
Due to having extended family members from both the city and the countryside, Stone was quite familiar with the Yorkshire dialect.
Stone grew up eating quick, cheap meals as a child due to his parents both working jobs and not having much money. This led to often repetitive meals.
Specifically, Stone got tired of eating spam after having it so frequently during his childhood for school lunches and meals at home (dishes such as spam fritters, spam salad, spam yorkshire breakfast, etc).
He definitely preferred fish and chips more. That was something he got to enjoy later in his childhood, likely during his early teens with the more available abundance of commodities and food in Britain and higher standard of living in the late 1950s and early 1960s.
Stone absolutely had beans on toast during his childhood.
Stone never had a dessert until he was 6 years old due to the rationing of food and sweets persisting in Britain until 1954.
Having been raised on food with not very strong or spicy flavors, Stone cannot handle spicy food whatsoever.
Stone was solid-milk lactose intolerant.
His schooldays were somewhat miserable for a good part of his childhood due to the British school program of making children drink milk.
He had to drink milk (despite being solid milk lactose intolerant) after turning red during the one time he tried Indian food at an Indian restaurant.
Stone and the neighborhood kids played with undetonated bombs and warheads (left behind by the bombings of WW2) found in the area of the city.
Any explosions he heard in the distance sometimes were something he just chalked up to undetonated bombs and warheads going off.
Stone definitely got into trouble (and also fights) in school during his childhood. It was common for him to be a frequent visitor to the office of the headteacher/headmaster to face corporal punishment like canings.
Still, that didn’t deter him from getting into trouble. And it’s that same stubbornness and also experience with fighting dirty in brawls that has him pushing through the military and eventually joining the SAS later in life.
A special thanks and shout-out to @zombie-nymph for working with me to come up with a lot of these headcanons about Stone's background! It's really interesting thinking about what Stone's childhood was like considering how he grew up in Post-WW2 Britain where things were still rough with rationing still being around and bombs still embedded in the ground along with the economy back then being what it was.