How does 鐘頭 come to mean hour? I know that 鐘 means clock so am I right in saying that 鐘頭 means head of clock which becomes hour?

If it's the head of the clock, is it referring to the minute hand being at the '12' (I.e the top of the clock?)

If so that would be very intuitive and makes me appreciate the Chinese language further!
I think you got the idea of 鐘 means clock and 頭 means beginning. It means the beginning of a 60 min cycle in the clock. So it turns to mean hours.