I also took mine completely apart and cleaned the parts with warm soapy water and a stiff brush. Wiped it all dry with shop towels and then let it air dry for several days. During re-assembly, I applied a very, very tiny amount of white lithium grease to rear track on the back side of the main vertical thingy and iirc, someplace in the mating gear thingy. (EDIT: the strike through parts are me remembering the D2). I think oil would probably be a mistake.
There was a time when people were giving these away and putting them out with the trash...at one time, I had four or five D2 and D-ii in various states of completeness / disrepair in the early 2000's. I fixed most of them up, gave some away to members here. I still have a D2 and some spare parts in storage.