Barend Polak had become a widower in 1938. He lived with his adult children (a few of which were married) at 16 Johan Keplerstraat in Amsterdam. There were four children: Alexander Polak, Samson Polak and his wife Frieda Polak-Grüneberg and another two children who survived the war.
Barend Polak bought three Sperre-stamps via a certain Wijbrands in exchange for cut diamonds for himself, his daughter and her husband. Despite the Sperre-stamps, the family was picked up from their home on 29 September 1943 and deported via Westerbork to Bergen-Belsen.
The archive of the Stichting Sieraden-Comité contains a statement of the right to inheritance, among other things.
NIOD, Records Stichting Sieraden-Comité, box HF 11, file 156
In addition, Jokos files (numbers 33457, 3804, 3762) on this family or other family members are at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.