Isaac Engelsman was married to Stientje Bas. They attended the wedding of their daughter Marianne Engelsman to Harry Gobas. The marriage was performed at Westerbork transit camp on 30 August 1943. The parents signed the marriage certificate.
Record of marriage certificates of the Westerbork municipality, currently at the archives of Gemeente Midden-Drenthe in Beilen
In addition, a Jokos file (number 893) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.The Jokos file reveals that a claim was lodged for compensation for valuables surrendered to the Lippmann-Rosenthal looting bank (L-claim, number 3115/14419).