After printing a couple other models that didn't seal properly, I decided to pick a well-designed model and make a few changes to seal it as much as possible. There are now three versions of the tray:
For the first two, I've reinforced the desiccant opening, provided an improved snap-fit lid with a tab to indicate the proper orientation, updated the funnel adapter to fit into the container better, added the funnel, and added brims to the two funnel parts. The funnel can also be use with this AMS Desiccant Pod.
For the third design, I've made the desiccant tray shorter, and inset the lid, to make it flush, and so it can be concealed behind the original AMS lid. I've also made the desiccant openings deeper, so that the top is much sturdier.
Note: See the attached photos for the best way to insert the lid. If you insert the left or right side first, then press the other side, you risk breaking the model. Please insert the edge closest to the logo first, then push the tab back towards the other tab. It may be a bit snug, but if you insert it at a slight angle the first time, you can then easily slide it into place.