The 1973 Worlds was won from a four man break containing, Gimonde, Maartens, Ocana and Merchx.
I have the "L'equipe Cyclisme" Magazine reporting on this world champs. It is in very good condition and for sale at $18 plus $4 post to the US. The magazine also has a full page colour photo of Hugh Porter going flat out to win the world Pro Pursuit title!
Regards
Martin Coopland