Got a couple Nikon DP-11 finders working properly, so they weren't jumpy anymore. Ring resistors were a little dirty, so ran the wipers back and forth over them a few times. Smooth as glass again. Also cleaned off the black paint from one DP-11's nameplate. At the moment, have a MS-1 battery clip soaking in some vinegar overnight in hopes of getting rid of the corrosion on everything.