The clipping may come from different places. It can arise in microphone, preamp or anywhere in the recording chain. In your case, If recorded signal is reaching 100% levels and it's peaks are cut off, then the clipping probably arise in recorder because the output of preamp is too hot. It is easy to correct it, set preamp levels lower.
If recorded signal is not reaching 100% levels and you have distortion, the distortion probably comes from microphone. The sound pressure level (SPL) is too high and the microphone capsule is giving too hot electric signal to the the electronics component inside mics body. When the electronic (FET) is overloaded, the distortion occurs. For this case the Naks have -10 db pad. It is between capsule and the electronic. The maximum SPL of Naks is 128 db. If you switch on -10db pad inside Naks then it is capable to record 138 db SPL. The 128 db SPL is sufficient with good reserve for our purpose. I think, JB mod is not lowering mic's maximal SPL, so you are safe here. I think too, you don't need 4.7 mod. I have read somewhere here it will not help to the Naks. Originally it is developed by Chris Church for mics AT853. This mod is not intended for all electret mics. You could unnecessarily lose some db in preamp input.