Hello Wouter,
You don’t give the dimensions of your safe but from the pictures it can’t be far off 36″ high in which case the weight will be approximately 7½ cwts. or 380 kgs.
It is a Milner List 2 made some time between 1875 and 1895. If you can find the serial number I can give you the exact year. It will be stamped into the top edge of the body close to the hinge and will probably be four figures with a letter prefix. There will also be a bigger number further to the left which will be the lock number but doesn’t necessarily relate to the year of manufacture.
Milner was the largest safe maker at the time and safes would come in barge loads to the Clyde from the factory in Liverpool. In the 50’s I used to service the safes - all Milners - in the City Chambers, about 30 of them throughout the building. May even still be there!
