Head Gasket to fit:
Leyland Marshall 
255, 262 - Leyland Marshall (Engine, 4.98DT)
344 - Leyland Marshall (Engine - 3.4TD) from serial no: 2443
384, 4/65 - Leyland Marshall (Engine - 3.8TD) from serial no: 40899
462, 602, 604 - Leyland Marshall (Engine, 4.98DT)
270, 272, 472, 702, 704 - Leyland Marshall (Engine, 4.98NT)
282, 482, 802, 804 - Leyland Marshall (Engine, 4.98TT)
JCB
2D - JCB (Engine - 3.8TD)from E40899
2D - JCB (Engine - 4.98NT)from E40899
2D - JCB (Engine - 4.98NV)from E40899
3 Mk11 - JCB (Engine - 3.8TD) from E40899
3 Mk111 - JCB (Engine - 3.8TD)from E40899
3C - JCB (Engine - 4.98NT)from E504/1404
3C Mk11 - JCB (Engine - 3.8TD)from E40899
3C Mk111 - JCB (Engine, 3.8TD)
3C Mk111 - JCB (Engine, 4.98NT)
3C Mk111 - JCB (Engine, 4.98NV)
3CX - JCB (Engine - 4.98NT)from E504/1404
3D - JCB (Engine - 3.8TD)from E504/1404
3D - JCB (Engine - 4.98NT)from E504/1404
3D Mk11 - JCB (Engine - 3.8TD)from E40899
3D Mk111 - JCB (Engine, 4.98NT)
3D Mk111 - JCB (Engine, 4.98NV)
4C - JCB (Engine, 4.98TT)
4D - JCB (Engine - 3.8TD)from E40899
Manufacturer part no(s) for reference:
81300238 - JCB
NKJ202 - Leyland Marshall