I wonder if the Johnstons in your images are related to these Johnsons (I'm not sure if one or other of us has the wrong spelling of Johnstone / Johnson or if they are different families).
My grandfather who lived in 87 Sefton Road had a sister named Theresa 'Tessie' who married a merchant seaman called John Johnston. He had a brother Robert / Bob. In the image the tall lad on the right is John Johnstone. Next to him is my grandad Joseph Halsall, then Bob Johnstone. The older man on the left I am unsure of but remember that the top of one of his ears was shot off in the war.
When my dad and his 3 brothers and 2 sisters lived in Bark Road and later Kirkstone Road the two sisters would often push their doll's pram to 87 Sefton Road to visit family. As often as not, if John Johnston was there, they would find on their return home that a piece of meat would have been tucked under the doll's blanket. A discrete way of supporting a family with lots of mouths to feed. John J no doubt obtained the joints of meat through his work in some way or other.