The Churchyard Register with Plan Ref 2736/20 is available to view on Findmypast and I advise that it is browsed. This register gives details of grave furniture, such as headstone, kerb etc and details often of those buried in the grave. This is where I download the copy of the New Extension Churchyard Plan, I have not found any other plans of the Churchyard for St Mary & All Saints, Plymstock. https://search.findmypast.co.uk/record?id=gbprs%2fply%2f004635151%2f00001&parentid=gbprs%2fply%2f004635151%2f00001&highlights=%22%22&_lang=en