Michael,
This is stunning work. The fact it's in card makes it even more impressive. Gorgeous modelling, on par with any scratchbuilds I have seen in brass or styrene. I might try this as a relatively inexpensive way to try building something new, or something with new (to me) components or challenges. If I can ask, what weight cardstock do you use? And what other types of paper or card would you recommend to a newcomer to this type of building?
Lastly - that rivet press is great! Did you make it, or buy it somewhere?
Stunned and impressed (and eager for more!)
Amanda