Lowering action on floating violin bass bridge

I recently acquired a late 60s Conrad (Aria?) violin bass. See photos. Not surprisingly, the action is pretty high as you go up the neck. Any tips for lowering the action? That's a string dampener on the bridge...

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Ha, we meet again. First do a setup and assessment.

There should be height adjuster wheels between the upper metal bridge and lower wood bridge. If there is no more room to move, sanding the bottom of the wood bridge is typical. Or shimming the neck.