After finishing the frame and attaching both panels, i added the rotary encoders. I tried first using mouse wheel encoders because of the thickness but i wasn't quite happy with the results. It was difficult to and not stable so I replaced them with normal short encoders. There are 6 such encoders needed, or 7 if you wish to use one for the altimeter setting. These encoders may be a couple of mm thicker, but that doesn't make e big difference. If you really want to have no gap between teh screen and the bezls, you can leave the bezels a bit biger so they touch the screen. In my case i didn't do that because I was happy with the result. Link on ebay for short encoders $4.17 10 pcs.