This is definitely the smallest watch I've worked on so far, a Rotary 9Kt gold ladies ring watch. I have not done a walkthrough as it is just a basic manual wind movement and these types have been well covered in the past.
It was not running when I received it, but luckily it just needed a good clean and oil and all was well. It is now holding +9 seconds per day which is more than good enough for a novelty watch.