Actually, the twiddling has worked for the most part! The needle is much less jumpy now. Thanks for the feedback on the foam kits. I was planning on replacing the foam on the hinge side of the back as well as the door channel seals as they are gummy. I wasn't too overly concerned changing out the mirror cushion though.
Door channel seals are more for moisture and dust, not light. I've taken them out of several Nikon MF bodies and never had any problems.