My firts trip to KNP was in the early 50's. My folks were farmers (1 farm in Eastern Transvaal - Lothair/Warburton and 1 in Natal - Baynesfield/Richmond). My Dad would take one of the farm 8 ton trucks loaded with all the "luxuries" one being an old parrafin fridge for the ice in G&T's. I know we ate a fair amount of mealie meal for breakfasts and pre-cooked poitjies for supper. Tea & coffee was always with condenced milk or tinned evaporated milk.
Trips into the park were of a shorter duration than they are now days because of the problem of keeping fresh food etc cold. My mom would follow in the car (1954 Buick)with my sisters and the nanny, whilst I rode with the old man in the truck. It was normaly a very early start when leaving the farm and I always remember Dad breaking into song as the sun came up, something that kind of sounded like the old song "Oh what a beautiful morning, Oh what a beautiful day" from the musical "Oklahoma".
By the way, in regards to the clothing, he used to farm waring a pair of Khaki long pants and and an old tweed jacket and his trade mark every single day of his life was a rose in that dusty,sweaty old jacket's lapel which he picked from moms rose garden every morning.
These trips were usually done in conjunction with uncles,aunts and cousins, so it was always a big group. Once the truck was offloaded a tarp was rigged over the back of the truck for all us kids to sleep under on stretchers and often the men slept under the truck or in hammocks tied between the truck and a tree whilst the women slept in the bungaloes or tents. The old buggers probably could only get as far as the truck after the many G&T's around the fire
By 1958 or there abouts the fridge was replaced with a "Zero" parrafin chest deap freeze that took 4 labourers to load onto the truck and the trips would then be of a 14 day duration. I don't recall him ever taking any pics in those days, so can't help out in that area