Have you ever noticed when you use super glue and repeatedly knock off a part and reapply it, there is either a edge or a rough texture around the surface? You can take advantage of this effect by simply apply thin super glue on the surface that needs to be textured, then use a old brush or a piece of scrap plastic and stipple the part to be textured (more coats of glue can make the surface rougher). When the glue drys you use a fine sanding stick and sand some of the glue down, more or less to your preference.
If you have any questions, post it, someone might have the same question.