Carbon 15:
Looking back at my post, it reads a little more critical than I intended. Sorry about that. Was just trying to point out possible areas / ideas worth thinking about.
I your work it is fantastic. If you ever wanted to have a "working retirement" one day, you could probably do very well with these ... in your "spare" time.
Note: The rod down through the top is a stroke of genius. Great idea! You know, if you ever needed to lock it, you could probably modify it to take a lock / bolt up there pretty easily too.
Finally, you're absolutely correct, that is what insurance is for!
Gunner