Klöckner-Humboldt-Deutz

Air cooled but after that not sure of anything as the info I have from a very poor photo of the data shield doesn't seem to fit a specific model.
I can read '1 Cylinder ' on motor block but shield seems to read F2L which would mean 2 Cylinder. Date of manufacture seems to be 1957 & rated at 18hp which seldom appears on Deutz pages. 
Anyway nice tractor & in use.