A realistic value in the US is $1500-3000. A good deal of value is based on condition and originality. If there is a wood holster/stock add $, if it has a matching serial number add $, if it has a leather harness add $, tool etc....
The value could be less than $1500 if there are issues, MM parts, signs of rust, loss of finish, re-finish, etc......
I cannot advise you on what the European value would be.
Regards,