Regarding the latest design, Richard asks, “can the edges be modified to fit with the space shown in the attached sketch?”
Short answer: no. I reduced the thicknesses as low as I could go and still get reasonable factors of safety. It is thinner, but it’s still not half an inch thick at the edge.
Further, the retainer ring will have to be machined after a couple complete sandwiches have been made, to find out how thick the final part is including adhesive.
There’s also the question of how it’s sealed into the midbulkhead. I didn’t add an o-ring gland. I expect silicone would work, as long as the parts are kept at a relatively constant temperature.
I remain not a fan of this overall approach.