The last document you have posted is from the Register of Seamen Series III. 1853-1857 The first one you posted is from Series II. 1845-1854 The number is his personal ticket number.
The ticketing system was widely unpopular and was a discontinued in 1857 as unworkable. From that date no Central records were kept until 1913. The only information is contained in logbooks and crew agreements.
It is believed that
most of the central records between 1913 and 1920 were destroyed. It would seem for part of the period that tickets were issued Royal Navy and Coastguard personnel as well as merchant seamen were given tickets. I checked the online Royal Navy records. Your man is not listed. That said the records only start in 1853 and it could be he was RN before that date.
I think you are correct with your belief that the vessel was HIMALAYA. Lloyd's Register has one vessel with this name in 1854. A Barque (sailing ship) built at Sunderland in 1840. 403 tons, Master Langford, owner Marshall, registered in London.
However there was also a P & O steamer with the name completed in January 1854.
It would seem both vessels made sailings to Australia in that year. A ship with the name HIMALAYA docked in London in October of that year. Without consulting Lloyd's List I am unsure which vessel it was.
Initially I would search Trove
http://trove.nla.gov.au/newspaperTo see if there is anything in the Australian newspapers of the time. Also there are several ships arriving in Australia websites. A post on the Australia Board should give you the links.
