If you imported the catalog tape to a new enviroment - then you can restore files from the catalog tape only.
If however you want to restore files for a different tape......
1) is this new enviroment a working enviroment - or are you trying to do a catalog recovery to this new envrioment - meaning are you trying to recreate your original backup master on this new server - if so you are going about it wrong.
2)if it is a working enviroment and you want to restore a different tape then you need to import that tape.