While following this thread it occurred to me that it might be interesting to see what George Redmonds has to say about this kind of issue in his "Surnames and Genealogy: A New Approach". The index doesn't include Pickstock or Pickstone, nor, from a quick skim through, any names with similar suffixes. However, in a section on suffix confusion (p.143ff) he notes that the suffixes Brook, Brough and Burn were quite often interchanged; these sound quite different to a modern ear, yet he quotes examples from registers such as "Blakburne alias Blakebrooke" (there is here, admittedly, a similarity of meaning). This kind of thing is said to have occurred more as surnames spread to areas where they were not well known, often with assimilation to those that were better known. In Appendix 3 (p. 205ff) he lists further examples of suffix confusion. Again, Stock and Stone are absent, but he begins the list with the comment, "An unaccented suffix was particularly susceptible to change, and could be confused with almost any other frequent suffix." In the light of this I would be inclined to keep an open mind on the Pickstock/Pickstone question - I certainly wouldn't want to rule out the possibility of one changing to the other. Arthur