I have a Pentax 645 Matte Focusing Screen for sale. I believe it will not fit the 645N or D cameras.
There are a couple of light scratches, which should not affect usability too much.
I do not have the original box, but will securely package it.
A photo is here: https://picasaweb.google.com/1041315...Ku5gICok5T9jgE
USD 45 (including worldwide JapanPost EMS shipping)

Thanks for looking,