Thanks for the interesting messages and, don't worry, I will be very careful with the drawings. I think they may be tracings rather than the pen on cloth originals.
I live near Derby and Paul is over in Staffordshire so we can easily meet up and sort through what's here. We'll then be able to see if any of the lot I have do fill in the missing gaps.
Next step is for Paul and I to meet up, drawings in hand.