Jack99, you were not confusing; my response was. My concern, which I did not express very artfully, was that the versatility granted by access to a vastly expanded suite of daily powers through a magic item in itself might be unbalancing. 4e takes great care to ensure that a single character does not have enough abilities to find an optimal response to any given problem unaided. That seems very sensible to me, and expanding a list of daily powers with a magic item permits a creative player to do a lot more things in a tough situation than a similarly situated player without the same magic item. I think that your suggestion does a nice job of capturing the feel of the original item, however, and I intend to use it. I'll let you know if it causes any significant problems.
To those who suggested that 2e characters are not convertible to 4e, I respectfully disagree. As I mentioned earlier, none of my players had any difficulty finding finding a way to build their character concept under the 4e rules. And in addition they're very pleased that the polearm fighter, for example, is different mechanically than the greatsword fighter. The faceman/skillmonkey who was an oddball thief in 2e actually is better actualized as a 4e bard. The mage who likes to blow things up is still trying to figure out whether a 4e wizard, warlock, or sorcerer would best suit him, but any one of them would be in keeping with his vision. We have a few details to resolve, but none of them will be deal-breakers, and I'm pretty sure the result ultimately will be successful.