Well, you are missing the becketts, as well as the outer housing which encloses them, into with the air control valves are screwed. I would think that's more than just a little fabrication, though I have seen people do it with both fancy clear acrylic and ghetto large PVC
Or just buy the part as in the link you provided.
How tall is that skimmer. I have two becketts on my skimmer, and even with added height, I'm not sure that would be enough for such a large system, though I am admittedly unfamiliar with this particular skimmer.