All I can tell you is, that my source says that only one Willeme K-116 with Karosa-bodywork for CSAD has been built in 1955. I attached the only two known (unmodified) pictures.
A similar Willeme from 1953 with different cab exists in France. Picture attached
These trucks had a 18-litre 8-cylnder-inline-engine with a power range from 175 (K-115-6) to 225 (K-116) HP. Advertisement of a Willeme 115-6 attached