Nikon D7100 tripod thread repair

I recently bought a used Nikon D7100, upgrading from a D3100. Unfortunately I missed the broken bolt in the tripod threads when inspecting. In an effort to extract the bolt, I have tried:

1. Superglue + small drill bit on the bolt (glue snapped instantly)
2. JB Weld + small drill bit (the JB Weld broke almost instantly)
3. Drill out the bolt and use a bolt extractor (left-hand threaded)

When trying #3, I heard a faint crack, like plastic cracking and now the tripod thread spin with a small bit of resistance. The bolt is still solidly stuck in the treads.

You can see some close-ups of what the situation looks like with the bottom cover removed. What are your suggestions of what to try next? I tried removing the iron connection sheet that houses the tripod thread but I cannot seem to remove it via the bottom access panel. I am open to all ideas here, I really want to avoid spending another $300-400 on another D7100 body or similar, just because the tripod threads are screwed. The rest of the camera works fine.

P.S. I want the tripod threads so I can secure the camera while working on a slide digitization project. My casual shooting does not need a tripod.