Thanks, guys. Splinter - I was wishing I had a laser for those rings!
I didn't mention that I made one failed attempt to use the CNC and a small bit to cut them out. I sandwiched a stack of 4 veneers between 1/4" plywood, each veneer backed with blue tape, and made a toolpath to cut out a set of small and large rings. The tape did keep the veneers intact, but it also created a bunch of gummy sawdust that was not practical to scrape-off the fragile rings.
I'm deferring work on the final two balloons while I consider other options. The manual cutter method worked, but it was fussy and was easy to mess up. There still may be a path using the CNC. I have 1/32" diameter end mills that wouldn't be as torturous to the wood as the 1/8" bit used in the experiment above. I'll post if I give that a try.
