Hello,
CR1, 2 and 10 cards are from the Fourth Register of Seamen otherwise known as the Central Index Register. He will not have a CR10 unless he served between 1918-1921.
CR2 cards record foreign voyages so I am not sure what Newfoundland mean when they say he was HT articles. That card indicates if correctly written up than he was foreign at the time. The otherside of the CR2 also has an engagement date of 25 October 1925 so obviously sailed on previous voyages.
Did you ask TNA Kew to check this file BT 381/353 (1939 Crew Agreement for JAMAICA PIONEER) which I believe will be the key to finding his service back to 1927.
Not all seaman's pouches survive unfortunately and appears his didn't so it will be unlikely you will find a photo in MN records.
Regards
Hugh
