I can remember those from my youth! There used to be tons of patterns available but now they are really scarce.
There is this one which is quite cute:
you may be able to adapt the pattern
Is this what you have in mind?(sorry no pattern there!)http://mickidmw.blogspot.com/2008/03/my-rendition-of-hanging-toilet-tissue.html
(its in the 29 march 2008 post )
It looks as if it is 15 stitches wide and enough rows to go over the rolls. I would measure over three rolls of tp and allow an extra 1" (or so) for space to slide the rolls in and then crochet the strip that lenght. You can either sew the areas in between the rolls or (if your math is good and its not 2am
) you can crochet the seams together as you go along to form the partitions. The top is just a decrease like in a dishcloth topper. The edging can be as complicated or as simple as you like. There are heaps of flower patterns on the net - so many it is hard to choose one!
EG. crochet 19 chainst. Dc in 4th chain from hook and every chain across. repeat until strip is long enough to accomodate the rolls then attach to the beginning row. Dc across and then work decreases on either side until only 8 dcs are left. Cover a round wooden ring with sc making sure the ring is completely covered and attach to the top of the cover. Work a simple shell edging along both sides ( sc, skip enough space to make the next dcgroup stand nicely. do dc group(2 dc , ch1, 2dc) into same space , skip enough space etc, sc, dcgroup etc)
I hope what I wrote made sense! Aks away if it doesn't!