As you can see from the pile of practise vents it took quite a while to get a perfect shape cut from the 25mm MDF. After about the fourth attempt I was considering giving up and buying some resin parts. After a tea break I got back to cutting and eventually completed two perfectly shaped vents, keeping my 100% record of manufactured parts. I did not take many photos of the whole process as they took so long to make, I was too focused on making them. The outer vents are 25mm MDF and the inner parts made from 3mm Card. All primed and sprayed and set into a thin wood pre cut shape which is painted red. This whole assembly is slotted into place. As you can see from the photos they are not fixed in place yet, just slotted in place, but work well.