For additional information about Eliazer Peeper and Estella de Swarte see the book Kopgeld of Ad van Liempt. There it is written that they were more or less coincidentally arrested on 8 June 1943 in the hall of the Central Station of Utrecht when two 'headhunters' had collected five Jewish children there.
In addition, a Jokos file (number 33036) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.