An experiment I'd love to do, but which isn't actually possible anymore, is run GPT 3.5 or the original 4 API release through a modern "agentic" harness for a task like this.

I think 3.5 would probably need more frequent intervention than a lot of harnesses give. But I bet 4 could do a simple JSON API one-shot with the right harness. Just back then I had to manually be the harness.