I'm confused now because the pick ups look a lot like X8962M wired in without the upright tabs.
It probably uses the standard 0-4-0 chassis as used on many of Hornby's models. You can find the service sheet here: https://support.hornby.com/hc/en-gb/articles/360016347079-0-4-0-LOCOMOTIVES-HP-MOTOR
These should be what you need: Hornby X8000 0-4-0 Tank / Diesel Loco Pickups (Pair) - Peters Spares Model Railways
Regards,
Cameron.
It probably uses the standard 0-4-0 chassis as used on many of Hornby's models. You can find the service sheet here: https://support.hornby.com/hc/en-gb/articles/360016347079-0-4-0-LOCOMOTIVES-HP-MOTOR
These should be what you need: Hornby X8000 0-4-0 Tank / Diesel Loco Pickups (Pair) - Peters Spares Model Railways
Regards,
Cameron.