Difficult?? But why? I understand is difficult to paint the deco plate but a Black cover for the deco plate is ok for me (maybe better placed as those photos show a bad place mentira) but the very bottom (the zone behind seen behind the escapement wheel), the very bottom should be easy to paint, isn't it?
@chris3007 would know the difficulty level involved as he did the paint mod himself on that specific portion below the balance wheel on the previous PAM438. So he's speaking from experience. But if you think it's easy enough to do, then please do show us the step by step (I would also suggest using a matte paint as chris' original attempt used glossy paint). Here is the thread I am talking about.
https://forum.replica-watch.info/threads/pam438-tuttonero-paint-mod.359592/