Help with engine identification

[MyJD450]

I have a straight 450, I'm told, with constant mesh transmission. 4 cylinder DIESEL engine with engine block casting number T24961. Coolant is in crankcase so parts will be needed. Does anyone know for sure if this would be a 4-202 engine and a straight 450? Any chance it would be a 4-219 engine? It has the 2 holes behind right heel below seat for original ID plate location. No SN tags are found anywhere on machine or engine designated locations.

Thank you