James Vallance has Henderson tomb aged 75 years old in 1780. It was 3 Dp E.
Peter Ramage has Henderson tomb in 1786. It was 4 Dp E. His wife Rachael Valenie (should be Vallance) has Farguharson headstone in 1798. It was 3 Dp E.
Do you know what 3 or 4 Dp E stand for?
I just found their burial records from Scotlandspeople website.
The Henderson Tomb appears to have been on the side adjacent to George Heriot's School.
These large identifiable tombs are sometimes used as a refenece point from which to find the burial place, so maybe that is what the 3/4 Dp E refers? Especially as most of the churchyard is to the East of Heriot's work gate.