Part Number:X1145, (S9573 & S2373) and L5662. This gear (S9573), axle (S2373) and worm (L5662) are not suitable for the later Hornby 0-6-0 locos which have a 42 tooth gear (the ones which have an unfortunate habit of easily getting stripped).
TRIANG HORNBY X1145 DRIVE GEAR S9573 28 TOOTH + AXLE S2373 for 0-6-0 X03 X04 SOR
S5453 Triang, Triang Hornby Wheel Keeper Plate, R351,R357,R751 3D print pt 3DPD