M1891 7.62x54R bullet

When younger,clueless me found this cartridge 3-4 years ago,i pulled the bullet out with pliers. Since it was rusted and dirty,i used sandpaper (facepalm) and sanded it,scratching and ruining it. I was bored so i pressed the casing (second facepalm),then threw it away (third facepalm). I believe that this one is rare. Can anyone confirm that? So,even tho i ruined it,is this single projectile of any value? Or is it something you can find easily?
Here it is by itself and between 7.92x57mm M75 and 7.62x39 M67.

To me, it looks like a Belgian Mauser (7,65 x 53, M1889). But without dimensions, that 's just some speculation.