From my research it appears ALL canvas pouches, whether they are original or replicas, have a small tool pouch on the right-most pocket. This pouch appears to be sewn on to the very edge of the pocket, in such a way that it tends to twist from the fron to the side of the pocket easily due to its lack of firm attchment.
Only a few of the leather pouches appear to have this tool pouch and it is attached in a very different method. The leather tool pouch is attached to a long strap that runs up the length of the pocket and appears to attach to the same button as the top flap is attached. On the two leather pouches that I have seen this tool pouch, the pouch is attached to the center pocket although I believe it could be moved to any pocket simply by removing the strap from the button on the center pocket and placing it on the button of either of the outside pockets. Comparing the ANH screen captures below to the pouches above it appears that the screen used tool pouch is mounted on the edge of the last pocket like the canvas pouches. Please note that in a few of the screen caps the tool pouch appears to be attached to a strap as is seen on the leather pouches, however, I believe the strap that is visible is simply the strap coming down from the top flap and is not actually attached to the tool pouch.

(note strap attached to tool pouch)
(click images to enlarge)
(note tool pouch attached to edge of pocket)
(click image to enlarge)