corrosion

Help! My dearly beloved brown Altman 3.5Q has stopped lighting reliably. I've tried different lamps, different circuits, switching plugs. I suspect it might be corrosion in the base but I have no idea how to clean that out. Any ideas?

Hey all! New member, first post. I work at a univ. and have been having light issues with some Shakespeares in one of our halls. We pulled the bases and noticed some corrosion in the sockets of all troubled fixtures. I'm looking to replace the sockets but havent been able to find an exact...