It is of Britishdesign and South African manufacture, a Pattern 1903 ro round bandolier.
Here is the information from THE source, Karkee Webb:
Pattern 1903 Bandolier Equipment Bandoliers
The P1903 equipment was in use by Great Britain and all Commonwealth countries, the South African cavalry bandolier like yours is fairly common.
As far as treatment to preserve it, DO NOT use any of the modern goops that contain petroleum products, one being Pecards. Use a light (very light) coat of either pure neatsfoot oil or lanolin.