Tennessee tax
If you built your plane in TN and bought parts here, you will have paid sales tax on those parts and can deduct their cost from the total value. I got a bit of relief by doing that.
I also had a hard time dealing with the local state rep in Memphis and ended up contacting the head guy in Nashville who was much more reasonable.
The local Memphis rep wanted to tax me based on the planes value rather than my cost.
Good luck.