As the "ball-screen" of the SM-58 is something of a defacto standard form for vocal mics, generic foam screens which fit over the ball are common and cheap. They are single layer and not particularly thick, maybe a 1/2" or so, but will help somewhat. Commonly available at music stores in a pack of 5, sometimes in multiple colors. I use them as windscreens on the DPA 4061 omnis I've mounted in spheres of similar size to make them slightly more directional at high frequencies, and in that application they completely suppress very strong wind.
Otherwise, try a faux fur "dead rat / dead cat" type cover.