Hornby R2877 BR 0-4-OT Pick Up part number

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.

I believe the only difference between X8000 and X8962 is that the latter has a short length of wire pre-soldered on, so you should be able to solder-on a short length to the former to connect things up. You can probably transfer these across from the existing before fitting the new ones into the chassis.

Regards,

Cameron.