The fittings below are for a mixer bar attached to a self contained shower. i.e not a wall. The attaching screws have snapped. I could get two new brackets, dismantle that existing one and start again or I could try and re attach via those screws, removing the broken ones from the plate and wall and screwing back on. The same question regarding best type of wall plug for the job exists for both those options however, if I choose to remove that plate has anyone any idea how? They appear to be brass rings, rather than nuts, either side of the plate. I've tried gently to unscrew without success, but I haven't used too much force yet. The other question there is advice on how best to remove the residue of those old screws.