Front panels
I just did this.
It took numerous iterations to get a fit I was happy with. Some tips:
Consider wearing mechanics gloves; You will need to flex the panel to install/remove it, and you will be doing that many times. The edges of the Kydex can be sharp and I have the abrasions to prove it.
Remove a little at a time.
Realize that Kydex is a Thermoplastic; if you need to alter the shape of the panel, in my case, around a wire bundle, you can gently heat the plastic with a heat gun, and reshape it. Be careful, though getting it too warm makes the plastic limp and it will set in that shape as it cools, ruining the original shape. I have worked with it before, so it might be beneficial to get a piece to practice on from amazon before you try it on the panel.
You may want to protect you instrument panel, if it is installed. You will be installing and removing the panel many times and it is possible to damage the finish on your panel if it is not protected.
Finding the correct location for the attachment screws can be a challenge. I ended up using a small Ryobi laser level. Set the level up to give you a line in the middle of the aluminum fuselage flange, then install the panel, position it, and drill the hole.
When you get the final fit, smooth the edges of the panel. I used 120 grit sandpaper and it yielded a pretty smooth edge.
Note that the map pocket area indents toward the fuselage skin. I ran some wires above it, some below it. I was able to run a #2 AWG wire behind it, so it does not go all the way to the fuselage skin. Probably have between 3/8" - 1/2" behind the pocket.
I added a nut plate to the very top of the door frame gusset; it made the panel sit nicely at the top...