Hi Dave
Like you I have only found an entry for Richard William Pugh in the 1871 Census and can find no trace of him after that, I was hoping that you might have some more information on him for me?
I knew my great-grandmother's name was Martha Pugh (nee Clucas) b.1845 Castletown from birth certificates / census records but couldn't find anything about her first marriage and only discovered the existence of her son through the 1871 Census.
I can provide you with details of Martha's other children and some of her grandchildren but can't really help with Richard William - by a strange coincidence though Martha's second husband (my great-grandfather William Robert Longbottom) is also often recorded as a labourer in a saw mill.
Derek