The pouch has been included with all the T-P equipped SE's, even though it was only designed to fit the full size hard King T-P (attaches with two screws & nuts at the back of the T-P, which are hidden by the light bar). Unfortunately, the pouch is too tall to fit the chopped T-P in the same way. I solved that by attaching it to the lid with double sided 3-M molding tape and adding a little strap to hold it closed. It's been hanging in there for 2+ years so far with no problem.
The leather T-P, while big enough for the pouch to fit standing up, doesn't allow for mounting with screws and nuts unless you don't mind two screw heads showing on the outside. The velcro idea sounds good, however, and has the added advantage of easy installation and removal.
BTW - I believe you will find that the pouch is made from the skin of that rare beast called a "vinyl", which is closely related to another animal called a "nauga". If you would like another one, H-D will sell it to you for approximately $23.50, part number 53165-89A.
Jerry