Acquired a quite nice small oval sidetable in a mahogan-ish wood, with a deep 35mm diameter burn on the top. Patched this with small piece of nicely grain matched red hardwood which looked to be an acceptable colour match before fitting. BUT, once in place, and scraped level, the colour is noticeably darker than the surrounding wood which has obviously sat a good many years in full sun. Have tried hydrogen peroxide to lighten it, but without much success. Somewhere, was pretty sure I had some oxalic acid, but can't now find it. The rhubarb has all died back for winter, so can't fudge with that. Question - is the lightening that might be gained with oxalic acid likely to give a close effect to bleaching in sun, or will it introduce other colour changes?