Well I tried to strip down the black unit but the hopper section is *really* not intended to be taken apart. Lots of sticky strips and a couple of tabs broken off.
Even a cheapskate like myself knows when to call it a day.

I could try to clean everything and put it back together but there's no guarantee that it would fix the problem and still seal in all the toner.
I have sprung for a new drum unit. They're pretty dear but even with the cost of that, I'm still up. You can't win 'em all.