« Reply #11 on: Friday 07 July 23 12:30 BST (UK) »
This is a very good point, and makes sense as to why SA Archives (for example) doesn't list the Orient in its collection.
I just found a few other resources about the Orient line (not specifically related to passengers), and it seems to have been under the P&O company (until a later acquisition). Skim reading the results does seem to suggest it was a commercial passenger ship and not part of the government scheme.
Adair, Ager, Anderson, Angel, Ayles, Badenoch, Bampton, Bannister, Bedell/Beadle/Beadel, Beresford, Bird, Blaesing, Brown, Butterworth, Clements, Eaton, Elston, Finn, Frith, Green, Groom, Hales, Hance, Heudebourck, Hollis, Maple, Menzel, Nancarrow, Noble, Oakley, Peed, Porter, Prior, Roberts, Sands, Scarlet(t), Sharples, Smith, Stickles/Stickells, Stokes, Sur(r)idge, Thurston, Tiver, Tulloch, Wade, Weeden, Wood, Young