The year of arrival should be 1895 as stated on page 14. If you add up the years in Australia that he gives in 1929, it totals 33 years. He states in 1924 and 1929 that he has been in the country for 30 years which is obviously an approximate rounding. I doubt that the actual day and month are correct, I have never seen a naturalisation record which is accurate, especially after that many years.
The General Gordon arrived at Port Pirie in July 1895 from Barry Docks which is just south of Cardiff. It was a cargo ship and seems to have mostly carried wool to the UK.
George was gaoled for 21 days on 10 August for theft from a person who I assume was another crew member.
http://trove.nla.gov.au/ndp/del/article/197614244The ship sailed for Newcastle on 16 August so George was not onboard.
This may be of interest:
http://www.archives.sa.gov.au/content/gaolsYou would need to contact SA State Records to ask if any non immigrant shipping manifests have survived.