"____ by Sir Walter Scott” is an anagram of "A novel by a Scottish writer” (7)
I believe the answer is:
ivanhoe
(Other definitions for ivanhoe that I've seen before include "Eponymous hero of famous novel by Walter Scott" , "On a hive (anag) -- hero of 19th century historical novel" , "Sir Walter Scott novel" , "romance" , "Book by Sir Walter Scott" .)