Without "all rights reserved", your work was basically public domain, and you were not able to license it the way you wanted to (because you did not reserve those rights, you could not license them).
When all members signed the Berne Convention, "All rights reserved" became totally useless, all that is practically the default mode for any work under the Berne Convention.
Of course, if there is no license statement, then IBM may not have provided you any license at all.