Thanks for posting. First of all, I have never attempted a tunuki and I applaud you for undrtaking the challenge. I think for all of your efforts, you can find a better piece of "deadwood" to really start the tree towards the best future. Plenty of twisted old garden junipers get left by the side of the road all the time. The best part is you don't have to try to save them.
I just read a great article on this. Google "behr appleby + tanuki" I found it to be a great read plenty of information to get a great start.
I'm sure you'll soon end up with a tree to be proud of, and the learning experience will only aid you in the future. Best of luck.
Dave