Thought I should provide an update.
I think last month I showed a drawing of the design. Later, I decided to refine the housing a bit more. Most other parts are done and I'm just waiting on the housing. The housing is really the crux of the mod. The changes I made are mostly cosmetic. You see, once I decided to use a 6 ml bottle rather than the 10 ml, I thought I can minimize the housing around the sides to better suit the smaller bottle. The end result is that the sides now are perfect hemisphere shapes, as can be seen below:
I feel this improves the look of the mod and makes it even more comfortable to hold.
The housing thickness is still 3mm throughout, which is tough. But to make it even more rigid, I added some "ribs" inside. I actually consulted with professional mechanical engineers in fine tuning the design. The machining process can sometimes deform a part, especially mine with its unique geometry, so I added ribs to be safe. The mod is composed of two halves so even a slight deformation or bend is undesirable. This is especially true for "door" half since it doesn't have much material in the bottom or the top. Added rigidity or toughness never hurts.
That's what I have been doing last week. It's already being made. Again, I made two different versions with minor variations, and this time I even asked them to make them in color (anodized). You already know what bare aluminum looks like and some folks are interested in colored versions.
Pics will definitely be up later this week.