I checked the Peugeot team rosters from 1959 onwards and Jan Janssen was never on their team. And yes in 1968 he raced for the Netherlands in the TdF wearing a Pelforth- Sauvage-LeJeune jersey and riding what looks to be a red LeJeune. But hey that's another TdF win for classic French iron....!
Peter Kohler
Washington DC USA