Siegfried Moritz Stoppelman was killed in concentration camp Amersfoort on 22 November 1942. He was a warehouseman.
Death books of Camp Amersfoort; these can be consulted at the website of the National Memorial Camp Amersfoort
In addition, a Jokos file (number 13895) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.