I recently came across this item, a badge with a pin on the reverse, about 1.5" across. Looks a bit like a badge a school prefect might wear? It's antique, maybe late Victorian/edwardian (1890-1910), tests as silver. Didn't know what it was but the only acronym I can find for 'HSOM' is Hogwart's School Of Magic...? And the three 'Z's? Initials? Lightning bolts?? Protective charms?? Way before Potter's time, of course.