Great project. With everything in the box in its place, I shook the box around like a banshee and nothing got mixed up. Love it.
The rockets were super tight in their spaces coming off my little printer, I ended up bumping everything up to 101% so they are snug and won't fall out, but it doesn't feel like I'm going to break one every time I insert it. I feel like I could even have gone to 102% and still kept them in place.
Slides were initially a little snug, but a few ins and outs smoothed them out and made them easy to insert and extract.
I did not do the card box. My cards are sleeved and I prefer these little inserts I made myself to keep cards together (see pic).