the trim ring that holds the horn button on my Nardi steering wheel has a series of holes on the backside that fit over corresponding nuts on the steering wheel housing. I think there may be 6 or so, of them. 2 of the holes have a small rubber grommet in them to hold the trim ring snug over the bolts. Then the horn button snaps into this. Does anyone know where I can find these rubber grommets, and also does anyone know if each hole was supposed to have a rubber grommet. I only have grommets in 2 of the holes?