Belgium Medal for 50th Anniversary of Independence [opgelost]

I acquired this medal for the 50th anniversary of independence, which I cannot find in Krause (Standard Catalog or Unusual World Coins). It is 30mm and it weighs 9 grams, similar to a France 10 centimes of the era.

Does anyone have any information on this issue?

http://www.elfreeman2.com/t18/9ni209o.jpg

http://www.elfreeman2.com/t18/9ni209r.jpg

Seems to be a locally issued medal, at the occasion of a school party (fête scolaire) in Mons . Ring seems to be missing.

Complete one on delcampe:
https://www.delcampe.net/it/collections/monete-banconote/gettoni-e-medaglie-belgio-altri/leopold-ii-roi-des-belges-50e-anniversaire-de-lindependance-nationale-fete-scolaire-13-juin-1880-mons-221597159.html

One like yours on ebay:
https://www.benl.ebay.be/itm/Medaille-Belgique-50-anniversaire-de-lindependance-Fete-scolaire-Mons-1880-/152084883714

Apparently it was supposed to have a purple ribbon :

https://www.google.be/search?q=%22fete+scolaire%22+mons+%2213+juin+1880%22&rlz=1C1AVFB_enBE760BE760&source=lnms&tbm=isch&sa=X&ved=0ahUKEwilrdDg153ZAhVMKsAKHZqVCKI4ChD8BQgKKAE&biw=1680&bih=944#imgrc=uPSqvWTdYMwXWM:
first pic

I don't know more. Commemorative medals with Leopold II on it is quite common. I don't even know which school in Mons could have done that. There are plenty of schools and even if some of them probably didn't exist back in the days, it's hard to say.

Thank you. Excellent!