Hope someone may be able to help as i'm getting conflicting 'advice' Does anyone know where i can get 2 x caps to fit the pipe in the pictures attached? one measures approx 6cm and the other 13cm. Recently unearthed this chamber after moving into a new home and finding the spare toilet was taking ages for the water to go down after flushing. After jetting i've been told that this was a system from the late 70's that requires the caps fitting to restore pressure in the pipe. Despite visiting all the usual merchants nobody can find a cap that fits either. Any help / advice appreciated.