Joseph Mozes Slap was a son of Mozes Andries Slap and Grietje Engelsman.
Addition of a visitor of the website
Joseph Slap was married to Mietje del Canho. She died on 27th of December 1938 in Amsterdam. On 31ed of July 1942 Joseph Slap remarried the widow 505407.
City Archive of Amsterdam, card Joseph Slap