Step one should be filing a police report with local jurisdiction especially if you have good documentation of the missing material. That report is the cornerstone moving forward with other complaints and actions. It demonstrates your seriousness about the matter given that filing a false police report is in itself a crime. LE may do nothing or they may pay Apfelbaum a visit. Either way it is the first step IMO.
When Rick contacted me privately on September 8 (prior to posting here) about this issue, I recommended that he contact Wendy Masorti at the APS to ask how best to proceed on this matter. I don't know whether he ever actually contacted the APS or not.
Hi Richard, I remember well the entire Apfelbaum Family. Bac in the 80's they were quite a powerhouse in the stamp world. Did you know that Martin was not schedule to go to Stampex London? He filled in for his son's wedding anniversary.