From the nature of the riveting and the 3-pdr Hotchkiss, I would say this is the same train as shown
But with the addition of a gun shield.
The “Defence of Ladysmith” title is misleading as, from memory, there was no armoured train in the besieged town.
Yes, there was no armoured train in Ladysmith, the title about "defence" is misleading. What about the caption re: HMS Terrible's Marines? Well, I may have got this wrong, but as I understand it, HMS Powerful landed at Durban on 27th October, and Capt. Lambton and his guns made it into Ladysmith on 30th Oct., on the last trains in. Thus Powerful's men were in the defence, not the relief, of Ladysmith. HMS Terrible arrived at Durban on 6 November 1899 when the siege was already in progress, so Capt. Percy Scott and Terrible's men were involved in the relief, not the defence, of Ladysmith.
The past is not dead. In fact, it's not even past.
Captain G.I.H. MULLINS, R.M.L.I. is on the QSA roll for H.M.S. Powerful (not Terrible), but received clasps for only Cape Colony & Natal. So he was not actively involved in the Defence or Relief of Ladysmith.
Patrols seem to have been conducted southwards from Ladysmith before the siege. Bennet Burleigh was laughed at when he was anxious to get out after the Battle of Ladysmith. Was it Ian Hamilton along with some other officers who were ordered South and who got out on the last train too. They pretty much had to shoot their way out and maybe used an armoured train to do so. As everybody here knows there was at least one train left in Ladysmith that shuttled wounded to the Hospital Camp once a day by agreement with the besiegers.
That train shed in the background is not at Estcourt and either is that town in the background. The caption reads "Armoured train at Ladysmith off to meet the Boers." From: Black & White Weekly Vol 1-2 1899-1900