Hi Tom, John Samuel Dewsnap was my great grand-father, and therefore I understand that I'm your 1st Cousin once removed.
I have a record of only 9 children of John Samuel and Mary, Percy Royden, Frederic, and Gerald Edgar dying in infancy. My grandfather John Edward being the sole surviving male. Ruby may have also died in infancy.All children were born in Sheffield.
John Samuels parents were George Dewsnap (christened 13th January 1811 at Sheffield Parish church) and Elizabeth Skelton, Mary's mother was Hannah Fowler, but I have no record of her Father Christian name.
I hope this of use to you for the time being. I also have quite a bit of information on the American connection, through Eveline Francis and Vernon Shaw.