Keep adding to Volume 10 till it fills up, then revamp the whole set to start filling the other volumes. For example move some movies from volume 2 to volume 1, etc.
You then have enough space another 15 movies.

When I find the time, I will come back to this set and re-do it. While my step mom (who I originally made this for) is quite content with leaving it as is, I feel I can do more with it by changing out the formula. I plan to keep the original design, but to change out the DVD with BluRay (as I personally have been going back and recollecting those versions). In doing so, I can shrink the set down to 1 disk per movie, as opposed to the current "2-disk for some" mode it's currently in. Many of the BluRay's are multiple disks, but typically these 2nd disks are just digital copies, and not really needed to be included.