WTT: 49mm for 46mm uv filter

I have a used 49mm Heliopean .75 uv -0 filter..chrome. Not mint since I've bought it used from someone but glass looks good and theres no scratches or dings on the metal. Looking for 46mm..either chrome or black..heliopan or leica uv filter. thank you

Why not keep the 49mm filter and get a 46 to 49mm step up ring?