Hi Gerd,
EV doesnt have the ability to move all of that data back to the original storage locations, when we pull those items back, either for indexing or access, it is a temporary measure and as such once we have completed that operation the temporary files are then deleted again.
In the past it has been a manual recall of those items and then an update to the SQL tables too as there is a reference in the tables to the Secondary Storage location that will need to be NULLed out or altered rather. It is a very manual process, hence why when you choose to migrate to secondary storage a warning will tell you that you cannot undo it, not 100% correct but it is a very manual process.
In relation to the Tivoli Storage Manager Client I am unable to help you as I do not know enough about it unfortunately, even if you can recall these items changes will need to be made to the SQL DBs to allow for the change in storage location now.
Have you looked at the NTFS to Centera Migration tool to see if that fits your needs as you are only using the DR550 as a secondary storage location aren't you?
If that is the case then the tool should be able to handle this - http://www.symantec.com/docs/TECH49828