Here is a stick that was purportedly quite popular, although there don't seem to be a lot of survivors. This is the "Turtle", or "Turtle's Standard Job Stick", which you could read in the shield on the illustration above if the picture were clearer. According to Speckter, this stick was manufactured on the East Coast between 1910 and 1930 by one David Turtle, a retired compositor. To better market the stick, Turtle stamped his International Typographical Union card number on the stick, thereby hoping to connect with other union compositors. Also stamped on the bed was an aide to copyfitting - a table showing the number of words to the square inch of various sizes of type. In some versions (including this particular stick) a ruler in inches is stamped on the inside of the rail as an additional aide.
This particular stick is 12-1/2 inches long, with a depth of 12 picas. The rail has a line of round holes punched through it, into which a small round post on the knee fits - the holes are 6 points apart, so the stick can be adjusted to picas and half-picas. The clamp is otherwise virtually identical to the Rouse job stick clamp.
I don't know if the knees tended to be fragile, but this one is unfortunately broken - a tendency to fracture may be why the stick is pretty uncommon, despite having been quite popular. This hypothesis gets further support from the fact that the illustration of the Turtle stick in the Speckter book shows a Turtle stick with a Buckeye knee, which obviously is a mis-match, since the rail is clearly punched with round holes while the Buckeye knee is not fitted with any sort of post to fit into the holes in the rail. Apparently the original knee for Speckter's Turtle wasn't around any more when he took the picture.