The short answer to Peter's question is that until the ship gets to port (in this case returns to port in a week or so) and they catalog and inspect the containers left, they will not know which containers are missing. Further, the shipping company may only know the name of the freight forwarder and not the actual name of the company that filled the containers or will receive the containers. Some of that might appear in customs documents, but a container of model trains may be listed as some "generic" contents for customs purposes. For example, a container of power tools may be described as that. It will not say whether the tools are drills, saws, sanders, etc. Additionally, there would often be tools with various product labels. Even if the container is listed as containing toy trains, since it would be shipped by a factory to a customs broker at the port, MTH/Lionel would not know for sure what is missing.
The consignees Insurance Company is probably most interested since the money has likely transferred under a "letter of credit" once the items were shipped.