Chiff and Fipple Forums

Hi,
Even though I got a beautiful Mk pro, I still quite like my old Optima, easy to play and nice for not disturbing the neighbors.
However, it's the simpler, non-tunable version with the plastic head.

Is it possible to tweak it to make it tunable, like I did on my little generation tin whistle?
Kerrywhistle does sell optima replacement headshell, so I guess it can be done.

Should I soak it into hot water too ?

Has anyone here done it?
Thanks