you can buy the smoke generators for them separately but they are pricey! Also the Bradleys use a separate heating element to generate smoke than they do to generate heat. As long as the internal heating element is in-tact and works, you can use it for sure! Just purchase yourself an A-Maze-N pellet smoker (maze for lower elevation and tube for higher) and then use that to generate your smoke, they run just $20-$35 on average. That's what most people on here do anyway even if their smoker does have a smoke source.
As for the hole, if there isn't a way to cover it up that is built into the unit, im sure you could walk around a home depot or lowes and come up with a creative solution to cover it. You'll want something stainless steel if possible, and certainly not anything galvanized. And if you need suggestions perhaps post some pictures of the issue/ hole your trying to fill/ cover and we can try to help/ offer suggestion.
Otherwise if the heating element in the unit doesn't work or isn't there, then you could still use it is a cold smoker, or buy a replacement element to make it a hot smoker.
hope some of that helps