Vacheron Constantin - Movement & Case Numbers

Movement & Case Numbers

Hello,

I just bought a very old Vacheron pocketwatch with numbers 24187 on the case. It is find on every back. Movement is an also very old - bridge movement without any no., I suppose as old as the watch. One of the back is signed: Vacheron Geneve,Cylinder Escapement Holes, 4 Jewelles, 24197. Also I get a key for the two holes (mainspring, seconds). Dial is engraved with Roman numbers and a castle in the center. All parts of the case and dial seem to be silver (case is very black) - Has anybody an idea, when this watch was manufactured - are there any further lists with ref.-no. on the internet. Thanks for any help and best regards! Mark