I'm back from working on the back end of the website, still a bit more to do but I'm give it a break for a day or two. Here, then, is the final shape of the dragonfly wing linkage. Notice how the parts cross over so that the wing pairs move in opposite direction. I've attached a file of the parts that I've used for you to try out if you are interested. The instructions are pretty basic but there are only a few parts and I'm sure you'll be able to work out what is going on  

From there it is just a case of gluing the wings to the wing stubs, making sure that they don't catch on each other as they move up and down.

I've then added a couple of linkages to pull the wings up and down. 

The next step is to mount this lot onto a blade of grass and connect the linkages to the pendulum.