Thank you again Jaager (Dean), Bruce and Derek, much appreciate the feedback.  No matter the country, era etc, this has been very interesting and I am learning a lot from the discussion.    Bruce is correct in identifying my particular period of interest being the mid-19th century, and by looking at the details within several of the posts I thinks the basics I have gleaned are that the butt shift and stagger pattern should : 1.  be a three or four plank shift 2.  the beam spa