I have a wash basin with pop up/down waste. It has been stuck in the down position several times, usually solved with a sink plunger which makes it pop up. This time that doesn’t work and it is completely stuck. (I think it was cheap in a new build house) I want to change it to a conventional plug waste. The sink doesnt have a chain stay hole, but it does have an overflow hole with a cover. Does anyone know if overflow covers are available with a chain hook? Alternatively what makes are reliable for a pop up/down waste. Thanks for your time