Hi Moonchild. It's great that you were able to come up with the dimensions. For what it's worth, when I bought "Woody", there were NO cases available. That is no cases that perfectly fit an 0-18. I had to do some checking and research. Ended up with a 10 year old (never been used) Harptone case (they're good, and cheap) that Stan found in Mandolin Bros. basement. The last one they had. Cost me about 100 bucks which is absolute peanuts for protecting a 50 year old guitar.
Rick