Pics are always good :-)
You can get the bungs at Beer-Wine.com
($0.79 each plus shipping), midwest is out of the ones from camiller's link but they do have these
that work just as well ($0.95 plus shipping). I have used both types of bungs and they work equally well IMHO, just the kind Midwest has in stock are 3 pieces instead of 2.
(I have also reused an Oberon 5L keg or two for beer. My comment about cleaning in my prior post was related to cleaning the dispensing spigot built into the keg).