@twiza Living in Cape Town and having tried most of the local watchmakers, there's only two that I would recommend for servicing a vintage Speedmaster. James Findlay at the Howard Centre in Pinelands and On Time Watch Service (OTWS) in Milnerton.
Findlay is great and very reasonable price, but he does not have an Omega parts account, so if you need replacement parts, he may not be the best choice. OTWS has an Omega parts account and has good customer service, but is somewhat more expensive. Good luck on servicing that beautiful watch!