I thought it was an "all-arounder" which was the Challenge model, until I learnt that that one was 531. In 1959, the hi-ten model was the Coureur. This post shows one a couple years newer (the blue bike), with the same fork crown and lugs: https://www.retrobike.co.uk/threads/.../#post-3241048 Not the best photos, but we are homing-in on a model identification.