Here is a link to a late edition of the Triumph Herald 1200, 1250, Vitesse and Spitfire Workshop Manual that does include the Herald 13/60. https://app.box.com/s/9ite5u16tvc4u83b7fnndwyxtjqcqpjg
An earlier edition is linked to from my website page: http://vitessesteve.co.uk/Servicemanuals. That could do with replacing as it a scan with pages out of order and missing later amendments.