A violin bass is also an archtop, so it is critical that the base of the bridge is in full contact across the radius.
It's a tricky job without being particularly difficult.
Usually you remove the bridge, place a piece of sandpaper facing UP on the archtop under the bridge position, and then sand down the base by leaving the sandpaper in place while moving the bridge - do you follow?
That should create a curved base to the bridge which exactly matches the shape of the bass.
Before you decide whether or not to do it, have a really close look at the base of the bridge as it is now. If it has already been contoured in this way then you might be best advised to leave well alone.
If on the other hand the base of the bridge is completely flat and therefore only really touching the bass at the inner edges, then it's almost certainly worth doing the contouring because of the improvement you'll get in tone and (maybe) volume.
If you want to use the top Hofner luthier in London, drop me a PM.