Well I'd say without the edge bumps and with a little less wear that piece would be XF, but that is just my opinion. This coin is in a very good shape though, regarding the fact that these coins were circulating for quite some time. I am collecting the Prussian issues of German Empire coins and those early mark coins with the small eagle (like yours) often look heavily circulated. This one would cost here in Germany probably around 60 € and if I was you I'd keep it :)
Best from Berlin