Another source w/ a good drawing (w/ dimensions) to get you started is my old favorite :
"Masterpieces of Furniture" by Verna Cook Salomonsky.
See plate 25, titled"Chippendale Style Sofa". It's a lovely Camelback w/ a high back, but it has no carving on the arms or crest rail.
Available cheaply as a used book on Amazon:
http://www.amazon.com/Masterpieces-Furniture-Photographs-Measured-Drawings/dp/0486213811/ref=sr_1_1?s=books&ie=UTF8&qid=1334113128&sr=1-1
It's a great resource, w/ measured drawings of lots of wonderful furniture.
JB