You might try this, go to a plumbing supply shop,get two black iron pipe caps 3 or4 inch. Then turn them upside down and drill a one inch hole through the middle of the cap. Take a peice of one inch round stock. ( or whatever dia., and length, fits your brackets ) Then weld them into the center of the cap. These make an excellant omni-directional skid shoe. they held up under my 700lb Boss snowplow through 4 seasons of commercial plowing. Cost was around $30.00.