I purchased 2 of these tables last year and am pleased with the overall look and functionality. However, they have not stood the test of time. The larger top has become wobbly despite careful handling. Umbra, please help. My issue isn't with the screws that attach the wood top but with the swiveling attachment at the top of the post. Is there anything I can do to restore/replace this part so the top doesn't tilt back and forth every time I move something around on it?