Sorry to report there is still no change with some stadiums, for example Navin Field 1934...
I using a Mac. I download the .rar file. I expand the .rar file and the Stadium folder appears. I open the models folder and drag the downloaded stadium folder into the models folder.
Sometimes it works. Sometimes it doesn't and all you see is a black screen that shows the crowd in the stands.
If anyone can offer some advice, I'd truly appreciate it.