Oh man, this is amazing. No need to apologize for taking your time, of course, this is fun to follow, at any pace.
If you want detailed critiques, I would recommend you send physical pulls to @JoeB and/or @pielock373. As you know, these guys are intimately familiar with the geometry of the shells and might have some thoughts to offer that would be easier to do when holding the object in one's hand rather than looking at pics. Just a thought.