Here is a short video I took of the original Victorian dressing box with secret drawer and the crude plywood mockup of the system we will be using in our Treasure Boxes.
Note the springs are strong enough to throw a piece of wood several inches. You cannot get this action with normal spiral springs. They do not have enough travel or force.
The reason I spent the money to have a professional spring company duplicate these springs is that I wanted the exact metal quality, dimensions and consistency that a company with modern equipment can produce.
I did talk with several metal artisans and realized that to produce a limited run would be expensive and the tension would vary among "hand made" springs.
I trust this very amateur video helps to understand how this system works. Contact me if you want to get a few of these for your own projects.