Hello, someone will be along shortly to tell you to do a introduction on the Intro and new members page, who you are, and something about the bike and any history,
(Pictures,,, they LOVE pictures here)
But more to the point, I am not able to help on the parts at this time but I have a 52 Plunger GF myself that I need to get around to putting up for sale, (needs total rebuild and restoration) But I CAN offer if needed manuals (Factory) and parts books digital so assuming file sizes are not too large, would be happy to pass them on if you dont already have access to them. They are invaluable of course in such a project.
Zimbabwe???? Holy cow! That must be challenging! I used to live and work in the middle east and parts of Europe and had the benefit of US Postal facilities (Military) and working on and maintaining a vintage vehicle or restoring one was challenging. I just shipped some foot pegs to a fellow in Italy and it took just over 30 days to arrive in his hands. I cant imagine Zimbabwe.
( I worked on a variety of friends cars and motorcycles while overseas, and had my own car shipped over, a 1963/4 Nova SS hotrod,, I had several orders held up because the order dept wrote back in those preinternet days "You did not indicate if your car has airconditioning or not, we cannot process your order until you fill out all the details" Never mind the fact my car was far from stock or never came with that power train. There were many such incidents like that)
I will add that the Magneto assys have their own parts and workshop manuals, And while i have some Smiths instruments materials, no actual sevice manuals or parts books. My hats off to anyone who takes on rebuilding the internals of a chronometric speedo, I am learning how on Magnetic instruments but the Chrono is a technical undertaking.
Best wishes...