I'll try and explain my method of making cloth roll surrounds. It's messy and time consuming, and doesn't look as nice as comercial ones, but it will last almost forever and costs very little.
I use thin cotton sheet material. Cut a series of strips just wide enough to fit from the speaker frame edge to the cone surface to be fastened to. Allow enough for the bend in the surround. All the strips should be as close to the same witdth as you can cut them. Now, remove the gasket on the driver and clean the frame by scraping until all old glue is gone. Carefully scrape old foam off the cone edge. Now, cut small sections about 1/2 to 3/4 inch wide from the cotton strips, cutting them with a slight taper making one end a bit longer then the other. Now, you'll need some silicone sealer and a can of naptha and a small mixing jar (I use a yogert container.) Pour about 1/8 inch of naptha in the cup (use in a well ventallated area with no flames or sparks around.) Sgueeze a bead of silicne into these and stir vigorously for while. What you end up with is very soupy silicone. Lay the speaker on it's back and make sure the voice coil is not rubbing. Apply silicne to both sides of the cloth and rub the cloth. Th idea is to saturate the cloth without adding a build up. Put a bit extra silicone on the cone and frame where the cloth is going and carefully place the large end of the cloth on the frame and the more pointy end on the cone and gently prees the ends down. There should be a roll in the cloth where the origional surround had one. Do the same for the opposite side of the driver. Now come back and repeat this with the next strip just slightly overlapping the first and gently rub the two clothe strips so they seal together. Repeat on the other side. Keep doing this until you get all the way around (this will take awhile.) You'll have to mix new batches of sealer every 15-20 minutes, as it starts to solidify. When the speaker is done and has dried a bit, apply a this coat over the whole surround and make sure there are no openings needing to be glued together. Let dry a few hours and it should work. Glue the gasket back on (I use silicoe, as it sticks to the silicne soaked cloth stips.)
I'd practice this on some dispossable drivers first. It takes a bit of practice to get the cloth just the right size and make everything go together just right.
Let your fingers dry for a half hour or so and the silicone will just peel off like shedding your skin. Much eisier than trying to clean them while wet.

All in all, a messy job to save a few bucks, but is a good alternative for unusual sized drivers. It works well. The surround is very flexible and soft.

Dave