The 1st Sunfish Worlds will have 56 entries. Garry Hoyt (USA) , Jeorg Bruder (BRA) , Rudy Thompson (VIR) and Per Dohm all sailed at the 1968 Olympics. Ken Klein, Dick Griffin and David Kelly will sail 3 sailed at the 1972 Olympics.
John F. Foster will sail FIVE (!) Olympics (1972-1992). He will also competed in the Bobsleigh event at the winter (!) Olympics of 1988. An interview with John and his son is here: https://www.youtube.com/watch?v=zX9P4urnUQk
Olympic sailing back then:
4 Olympic sailors at the Worlds will not be a record. In both 1972 and 1976 there will be 10 Olympians competing. 20 SF World sailors will sail more than 1 Olympics. At the top of the list: Hans Fogh: 6 times. John Foster 2nd (5 times). Paul Foerster, Peter bromby, Paula Lewin, Juan Maegli and Juan Torruella all will sail 4 times at the OG’s.
In 2021 in total 61 Sunfish Worlds sailors have sailed at an Olympics.
Finally: 2 Olympic Gold winners sailed a SF Worlds: Serge Maury will win the 1972 Finn class (5th at the SF worlds) and Paul Foerster will win the 470 class at the 2004 Olympics and and also win the 2008 Sunfish Worlds.