Your local autoparts store may have what are known as "shock" boots. They used to be very popular with the 4x4 offroad truck crowd. The upper and lower IDs measure about the same as the D58 fork boots. The ones that I just picked up (they are "Pro Comp" brand) only set me back $6.67 for the pair, inc tax. They ARE "fatter" looking in their outside diameter, but seem to be made of a better, thicker, neoprene or silicone-like material.