This reminds me several years back when at my buddies restoration shop and a customer brought in his C2 to adjust the door hinges, as a door wouldn't close and latch. Further examination revealed that the front half of the birdcage had rusted out.
The owner was advised of the enormous cost and effort to replace the birdcage. Customer said to do it as it was a one family owned car. I started a months long thread on the Corvette Forum with photos. I'm still banned over there for a few days but will try and find the thread and post a link here.
Great work on your beautiful blue Corvette!!