Hi - I have wall vents with cheap DIY style thin plastic hit and miss vents. So thin they rattle when it's windy. Vents need to be hit and miss due to an open fire but wanted something really ' hit and miss' ie can open when fire lit but really closed without draught when not. Can find brass, chrome etc but wanted white metal to be sturdy and match room. Can't find white metal ones anywhere, anyone have an idea please???