Hi,
I have just discovered this site and saw your post so i have just registered as well. I noticed the name Sives. I have this name in my tree also from East Lothian but mine is from the 18th century. Anyway i discovered there is quite a few name variants for this name, which you may or may not know. I have seen the name written as Sives, Seives, Sibbes, Civis, Civys, and Stibs. Just thought this info may be useful for future searches.