Part Number:X8597, X1544, L5509. See Hornby Service Sheets 131, 204, 220, 259 and probably others as well. make Supersized seem small. We hope that you understand.
Hornby L5509 (X1544) Class A1 / A3 Cylinder Block
HORNBY A1 A3 A4 SCOTSMAN VALVE GEAR, COUPLING RODS X1707 X1708 X515 X516 X1123