That being said... I found myself wanting a pinning tray that way better than a piece of cardboard. Im also too impatient to buy something and wait for it to get here hahaha. So I decided to make something. I looked around the shop and found a decent piece of wood and my grandpas old router.
I have NEVER used a router before, so this obviously wont be perfect. I may make a second, better one later.
I took a decent piece of wood and started making measurements and laying down lines. I decided that I wanted my pin slots 1.125 inches apart at their centers. So I marked the board every 1.125 iches.

After laying out my lines I choose the bit that I would use for the pin slots

I didnt take pictures of the next step, but what I did was clamp down my board to a table. I then clamped a piece of wood along my board to use as a guide while routing. I didnt used the lines as a guide for where the cuts should be, I used them to decide where the edge of the guide board should be.
I then started routing the pin slots. I did them in two passes. The first pass was shallow, the second a little deeper.

After routing the pin slots I marked (roughly) where I wanted my parts section and plug holder to be. I then started routing these with the same bit. I once again clamped a guide board down so that my lines were relatively straight. Since I wanted the parts section and plug holder deeper I decided to go with 3 passes instead of 2. I routed a square for parts, then just zigzagged across the middle. I made a plunge for the start of the plug holder. (By the way this was not a plunge router, i just held it above the wood then lowered it.)

After finishing the long section of the plug holder I switched bits for where the rim and key will sit. (Picture of that bit coming up next) since the rim and key need to be lower than the rest of the plug I cut them deeper. I did these sections in 4 passes.

Here is the bit that I used to finish the plug holder.

Now I know that this isnt exactly safe... but I dont have a table top belt sander. So I mounted this old sander in the vise for my ghetto sander. I even managed to keep all of the skin on my hands!

After sanding down the sides I decided to round off the edges

Which I did with this bit

After a bit of hand sanding everything that I routed here is what I ended up with.

I know its not perfect, but Im happy with it and it will do what I need.