Rebel was a German band that was created by guitarist Tommy Clauss.  John Lawton, ex-Singer of URIAH HEEP and LUCIFER'S FRIEND, was on a promotion tour  in Germany when Tommy Clauss  met him and to asked him to produce their album.  As it turned out, the vocalist (Mr. X?) was not working out, so Lawton stepped in the role and provided vocals for the album himself.  The resulting album is not as heavy as Lucifer's Friend or Uriah Heep, more or less falling in the post-Dio Rainbow mold.  Yes, Hold Your Head Up is a cover of Argent's song.