Warhorse wasnt a Peter Jackson Film, it was Steven Spielberg. Although PJ has some WWI tank replicas, they are a bit different mechanically to this one (And significant different to the originals) Heres a video on how the Warhorse Mk IV was made:
One curious question - why are some tanks female and some male ?
"Aristotle II IV 20-Nov-17 – A Bttn, 2 Coy, 5 sec, A24 Lt Rodgers JR - In action. Hit and burnt out at Marcoing W23 behind German lines. W1a Later recovered to Marcoing railway station by the British. A male tank. X11.111 Note: Mistakenly given serial number 2025 on Battle history sheet. 2025 is Arethusa's number."
and meanwhile "Britannia IV A Mk IV female tank which undertook a war bonds tour of the USA; not 2561 or 2668."