I have a Zither from cica 1890's. The zither is slightly warped, especially when tuned to pitch. What is the best way to return the instrument to its proper position? Clamping while slowly adding humidity and heat? Best ways to clamp?

Thanks!
Bill

I am happy to report that I was able to correct the slight warp to the fretboard of my zither. I used a violin humidifier on the instrument to allow for slow humidity to re-enter the wood. As I did that I clamped the fretboard and allowed the instrument to sit for some time. During the clamping process I would check the condition of the violin humidifier from time to time and add water as needed.
The neck is straight now and the instrument sounds great. Now to continue to learn the instrument.

Bill