Haydock sometimes collaborated with former Douay associates. In one case Father Thomas Penswick (1772–1836), a former classmate, translated  The Love of Jesus in the Adorable Sacrament of the Altar (1801) from the French of Henry-Mary Boudon. (Ironically, Penswick, who later became Vicar Apostolic of the Northern District, would have a disagreement with Thomas’ brother George, resulting in the latter's temporary suspension from his priestly functions.)
Haydock occasionally collaborated with former Douay colleagues on various projects. One notable example involved Father Thomas Penswick (1772–1836), an old classmate who translated  The Love of Jesus in the Adorable Sacrament of the Altar (1801) from French by Henry-Mary Boudon. This collaboration was complicated by a disagreement between Penswick and George Thomas, resulting in George’s temporary removal from priestly duties.