Well, what kind of gears are these? If they are brass all you need to do is clean them very well, brass does not need a lubricant to work properly. In fact it is worse if you do it, since mostly is gathers more dust and makes it worse.

If the camera is made of wood, you run the risk of getting the lubricant between the brass or metal gear and the wood, which can cause wood rot.

I am going to go against the grain here and recommend you do not lubricate, just clean very thoroughly, if necessary with a tooth brush, but leave the lubrication alone.