I have a 1936 Hart Parr 70 which I am restoring, The issue I have is the engine has no prefix/suffix to state HC or KD therefore I assume it is a HC. The problem lies in the carb installed on the tractor, I have an original manual from 1939 which shows the current carb to be the KD style. How else do I further Identify the components in the engine to prove one way or the other?