Engers brothers Leo (Leonard) and Johnny (Joseph)

Picture of the Herman Elte school, Amsterdam, 1928.
Probably the full name of Leo Engers is Leonard (born 1920) and of his brother Johnny: Joseph Isidor (born 1921). Their class mate Jette Pais (my mother) remembers that they had a younger brother, probably called Henri, and that their mother died at a very young age. This may explain why they were in the same class.
See also under their father's name Isidor Engers and their names on this website.