1949 Voortrekker Monument medal

I have a 1949 Voortrekker Monument medal that someone has removed the hook ontop so it looks like a coin now. How much does iet affect the value

Some ignorant people consider that if the object resembles a coin, it will be more valuable. But this is just smoke and mirrors and it alters the historical context of the issue of this object (a medal for schoolchildren). So in my opinion this greatly reduces the supposed value of this object. I say "supposed value" on purpose because this medal has no intrinsic value, it depends on the more or less interest that a possible collector could have for this event whose historical importance is not so obvious a few decades later.