I found it at one of those Taco Bell/KFC combo restaurants. I actually went in to get a Taco Bell Supreme burrito. However, I noticed some booklets on the counter that said "Original Recipe Bites." Inside it was chock full of great KFC coupons including the one for the bucket. I grabbed three of those buckets. Perhaps you can also find those booklets at a regular KFC restaurant.
The strange thing is that a few days earlier I was scouring the Web for good printable KFC coupons but couldn't find them.
I’ll look for them, thanks!