Ok, kiddos. I had a couple hours to spare between hospital dropoff/pickup, so I busted out a wood mock-up of my idea. I want to make it VERY clear that this was slapped together, and a quality piece would need more time and better calculations. This, however, does prove that it can be done.
I will stress some points;
1. The distance of "A" is to be exactly the same on every piece connected to the same armature. If not, the throw (radius of the arc) will be off and the device will not move.
2. If the side-lever design is unacceptable, then another alternative is to extend "bar 1" towrds the bottom of the picture where it can be activated by a push/pull means.
3. Using the thinner medium of metal, the blades would have a slight upturn to their facing edge, like on a propeller. Thus facilitating the blade passing over the one next to it in the retraction process.
4. Further improving the design, I would perhaps lengthen the radius of "A" to increase leverage.
5. The missing forward blade could be attached in a similar fashion using it's own lever because it would need to sweep in the opposite direction to save space. Alternatives do exist with more design modifications.
6) Some good old fashioned tweaking is in order to assure a smoothly operational apparatus. Measurements should be calculated and proper scale determined before committing to the actual cutting phase.
Hope this helps. 
