Will Book A includes a detailed plan of Robert's estate and how it was to be divided among his heirs. But I've never been able to figure out where the property was located. That plan was made in 1825, just 5 years prior to the McCully Grant. The McCully grant indicates that the "heirs of Robert Coates" were located west of Blair Lake and McCully's property.
We know that Hood Coates, who received allocation No. 5 of his father's estate, lived at Crawford's Hill and the 1825 map indicates that shares 4 and 5 were located on Crawford's Hill. Margaret Boomer said that this property was at the end of Coates Road near the Amherst Bird Sanctuary. So I'm starting to see how the piece of property described by the 1825 drawing could fit onto the landscape. Is the road at the bottom of the plan the road to Amherst Point?
Joseph Coates (and later Rupert) had a homestead near the Sifto salt plant but this was probably too far south.
If any Coates descendants have already sorted this out, I'd love to know! You can obtain Robert's Will and the map by purchasing Will Book A from the Cumberland County Genealogical Society. You may also be able to request just the will and probate documents for a fee. Unfortunately the map of Robert's estate division is not included with Robert's online probate papers.