Being UK-based, I'd always check out the Hitchcocks website for any RE parts. I've only had a couple of dealings with them, but they've been reliable and never had to question their quality. Because they are a quality supplier, you do have to remember that in the price you pay. You may also have to pay a premium for shipping to South Africa.
Others have gone to vendors on Ebay and have had mixed results. Sometimes you get what you pay for, sometimes not at all, and sometimes the quality can be a bit suspect. I'm afraid I can't give advice there. I suspect if you do a search on the forum, you might find reference to one or two vendors with good/bad comments.
Good luck with the restoration.