Tapner Jewellers - NSW
Uber Bizmeister John is the go to guy for servicing/repairs of antique watches. Has done so on several of my watches and the service is definitely 5 star. Very knowledgeable and a downright nice guy.
Highly recommended
Shop 1/60 Castlereagh St, Sydney NSW 2000
Google map: https://www.google.com/maps/place/?q=place_id:ChIJMYjhBkCuEmsRfCYYyZzrmXk