Updates: Huge thanks to @matt2282p for helping me with the sleeveless shirt issue, as well as recommending a better hat object. I just need to fix a few glitches but's pretty close now. I'm in favor of the sunglasses again because I figured out how to get the subtle shading looking nice (it's better in motion than in the still above).
So now I'm up to the last attire I wanted to do: Greed 2001. It's another sleeveless shirt, but with a collar and buttons. I spent a lot of time looking around and it seems like Baron Corbin's 2016 shirt model would work (with some serious adjustments). But I'm running into the same vertex blob issue. Now that I know about pozzum's awesome 00CA editor - I can update the file and get it closer to working - but I'm still getting like 2-4 vertices out of place that are causing issues. I followed Azn's tutorial, but I'm wondering if I'm missing a step, doing something wrong, or if that model just isn't meant to live on Dusty.