I gotta to admit I am very impressed with the South African Model Car Association.
They've been sanctioning organized slot racing in their country for 58 years, since 1966, and while I don't know the early history of the group, now they promote just two racing classes, Production 24 and Open Group 12, which I believe is a very wise approach.
And they report race results promptly and professionally, witness these images from their Facebook page, all posted the next day after the racing.
And for something really impressive, take a look at this PDF brochure produced for SAMCA's 55th anniversary race held in 2021. It's worth noting who wrote the foreword for this production.
SAMCA-BROCHURE-55th.pdf 18.92MB 56 downloads