I note no-one has responded to this so I'll jump in and give it a bump.
The business end of the TMB flattener consists of a regular T-2 thread (M42x.75). This is typically coupled to a camera of choice T-Adapter. It is possible to use a T-2 to 2" nose adapter in which a 2" filter could be mounted, however you'd want to ensure this is low profile as to not increase the overall focal length by too much.
Something like this would probably sort you out -
http://www.telescope-service.com/acc...l#fokaladapter
I'm afraid I don't have any pictures of an optical train. There are a few 132 owners here, not sure how many have the TMB flattener.