This is LSWR coaches 70 and 76. To answer the question of how these ended up in Wales. They got sold out of mainline service to the Army and were used on some of the military railways (Longmoor and Marchwood, possibly Bicester and others too) for many years. Then in the 1970s or 80s got sold into preservation on the Mid Hants.
The Mid Hants disposed of them in the early nineties as part of their cull on vintage carriages (eyesores taking up valuable siding space as the management of the time saw them). There were bought by a private owner who moved them to Blaenavon, and have been there ever since. Some work has been done by the owner there, but it’s obviously a massive task for one person - especially being completely in the open.
Will be interesting if they do return to the Mid Hants. Certainly a more worthy project than those LBSCR 4 wheelers they have. Swanage have made some noises about being interested too for use with their T3. So we will have to wait and see what gets announced.
The owner also has an Ironclad brake at Blaenavon which presumably needs a new home too. Hopefully it might go with 70 and 76 for future use with them at their new home.
Would a Restaurant Composite be in the Titanic boat train? I would expect in those days for a ship of that size there would be separate trains for First and for Third class. It was common on the LSWR for there to be three or four boat trains for a major transatlantic liner, and for them to be run as separate classes.
The British Titanic Society do seem sure that vehicles of this exact type were used on the boat trains to the Titanic. Presumably they have photos of the train which show this.
In any case the BTS seem committed to saving these coaches as an example of the ones used, even if it can never be proved that 70 and/or 76 themselves were involved.
Reading the article in ‘Rail’ the plan seems to be to restore them at Ropley. Then run them on the MHR as a Titanic boat train experience.