Alfred,
Thanks for posting this. Per our recent discussion, this is the one part that needs to be in good shape on any pump being rebuilt or another found from a donor pump. Many of the other parts can be sourced from metric bearing and seal suppliers. The nuts, screws, washers, brushes etc can all be had fairly easily as well. There are many places where the armature can be rewound and a new comm added. I have even been able to duplicate the tab washer and woodruff key using emachineshop that are critical to driving the bellows and impeller. The bellows though has been impossible to find, fix adequately or reverse engineer. I have my doubts as to the long term viability of replacing this seal with a normal radial type rubber lip seal as we also discussed. The Bosch diagram you were able to find does provide some glimmer of hope though. I was surprised that there actually is an NSN and a number of interchange numbers for that seal indicating that it was perhaps used in other applications and perhaps even still available. Hopefully, some closer to the manufacturers that pop up using these interchange numbers will be able to tell us if that is the case.
George