After gathering as many useful pictures as I could find, I held a ruler up to the computer screen and started measuring. I scaled all measurements to give a total length around 2m and staff diameter of 25mm. I'm not finished, but I'll be focusing on the head first, so here are my rough measurements so far. All numbers are in mm.

I was surprised at how narrow the head is. In my mind it was much bigger.

Next I began the hard part, figuring out how to make the head open and close. It is such a small movement, but it is vital to the project. I spent spent much of the day at work just thinking up designs in my head and here are two of the most realistic ones I came up with. Note that there will be a stiff metal rod embedded in the shaft connecting back to the control section of the staff. It will move forward and back to actuate the mechanism. Let me know what you think of the ideas or if you have any better ones.

Once I commit to a design I will begin construction. Then when the mechanicals are functioning, I'll start on the electrical. 3.5 weeks. I can do this.