I have just fitted a brass door knocker to my new front door. Should be a 5 minute job, only two holes to drill..Problem is the bottom hole I drilled went about 10mm out of line! The long threaded bolt which goes through the door has a brass domed nut but no washer. I have to enlarge the hole to line up the bottom part of the knocker, and really need a brass repair washer to cover up the big hole. I can find steel washers but not brass, any ideas? Thanks..