Actually, as you can see from my surname, Rennocks is a valid spelling. I am from England, living in Ohio now. My Great grandfather was from Leiestershire, England having moved south when his father moved at the end of the 19th Century. To this date most of the 'Rennocks's' in the England are still in Leiestershire. I have not got back beyond the begining of the 19th century, but I believe we came from Cumberland in the North of England and that our surname was first 'Ravenswick' which became 'Renwick' etc.