Ruth I think it is alright to call him "Derek". Mr. Schofield sounds very formal and I have met him and know him to be a very friendly person. I am sure he will not be offended by familiarity, indeed he may even enjoy it.

And if, by calling me Dave you are reminded of the marriage vows you nearly broke then I would be very happy.

How could you - a cowman? Surely someone from the local Borsetshire Agricultural College would have been available?   

Dave