Yes, they do.
They speaker frame had a single 1/4-20 stud that extended front the center down.
The box had a hole that slipped over the stud and a stamped steel wing nut secured it on.
http://nastyz28.com/threads/a-few-ca.../#post-3104203
The 1970 and 71's had a unique speaker grill that was a rectangle with welded in studs. sometime in 71 the corners were rounded. 69's were rectangles, but the studs were separate. They are a bit hard to find.