Only JTV files represent recordings. Other files, jta, jts, jtf, etc. are internal files. Under Documents, you can delete them from the library (but make sure you do not delete them from the disk!). If you find jtv files under Documents, select them, and click Tag in Action Window.
When say you found no jtv, did you mean you did not find them in the library? They are still on the hard drive, right?