Amazon Battery Box Vent Kit

316 stainless steel costs an arm and a kidney or three. If the batteries did not gas then a shiny brass job would work. More than likely the shiny job is chromed pot metal. And let chromed pot metal get a whiff of battery fart and kiss it goodbye. 18-8 and 304 stainless gets a white powder on it. Maybe appearances would enter the picture -- anything but a white finish would look better with chrome.