I think you're unlikely to achieve a satisfactory outcome by purchasing a replacement, whether or not it's intact. The plastics have become brittle with age, and regardless of current condition, are unlikely to hold up. Case in point, I recently purchased a lightly used 180 for some prototyping work and upon arrival, the lid plastic around the threaded inserts was better than any I'd yet seen. Only took a few open / close cycles before it too was crumbling.
You have a number of options (some outlined in this forum's only sticky thread), from JB Weld, to 3D printed reinforcements, to (my personal preference) pinning the halves together by sending counter-sunk screws through the back of the lid into the remaining thread at the base of the inserts.