Minor update, almost 3 years later. The game worked (and works) fine after that fix, but I should detail how I de-rusted the RF Shield, since I mentioned it earlier.
1: Dremeled Rust.
2: Soaked Shield in Vinegar (edit, after Niku-sama's post below: this was for longer than a day, to remove rust. Now, original post: ) (in hindsight, I could have simply done this, and nothing else. Dremeling wasn't necessary.)
3: Rinsed Vinegar off.
4: Dried.
5: Coated with 2 or 3 coats of VHT Rust Converter, let cure.
6: Coated with 2 or 3 coats of Zinc Weld Through Primer, let cure.
I also did this to a few spots of exposed metal on my old Explorer's hood in late 2018, and I have not seen any rust come back even now, so that's why I went this route.
- Austin