I've posted data and copies of documents for Peter Elder and some of his descendants on a website. The address is http://www.peterelderva.info/http://www.peterelderva.info/. See the Notes area, Elder family link.
I'm looking for a source document for the marriage of Edward Morris and Elizabeth Elder, relict of Peter Elder, by 1687. This marriage is reported by Wilkerson, but I haven't found the original record.