Hello again Dave,
Think your saying:
Horatio had bothers called William (your Gfather), Horatio, Abraham and James and a sister Marion - I think this is all correct except have Alfred instead of Abraham and also a Mary and another Ebenezer - think Marion may have died very young. Your Gfather was the youngest.
Horatio jnr did have the 4 kids you named plus a James, Robert and Thomas.
What was the name of your uncle who remembered this?
TW