I have only repaired a couple of indicators. I disassembled them, cleaned with ultrasonic cleaner and clock cleaning solution, rinse and dry, then reassemble, lubricating with watch or clock oil, depending on size of bearing. oil must be used sparingly to prevent it spreading away from the bearing. Gear teeth are not oiled. Oil on hairsprings may cause the coils to stick together if the devise is jarred. It helps if you have repaired a few watches. The skills are similar.