This is from a website that no longer exists that I saved to my PC in 2006, so the info is 14 years old:

"A good source of parts for Warner engines is Harmon Dickerson. He can be contacted at 573-449-6428 or by email at hdaircraft@cs.com."

Also this page has manual reprints:

http://warnerenginecompany.com/Warne...0Products.html