Officially, I believe that the first World Championships were the ones held in Helsinki in 1983. Could you explain your reasons for including the two before that (albeit asterisked)?
In 1976 and 1980 they held a world athletics championship to cater to the 50km (1976) and some other events in 1980 (10km and 400mh). This was because they were not being done at the Olympics. The official start was in 1983, but these were deemed World Championships as well.