In a different thread, Texasred posted this link, which should answer some of your questions:
http://www.v8cars.hu/oldsvin/decode.php
In response to one of your earlier threads regarding color, my brother gave me a book to decode all the different numbers/codes on the car. Quoted from the book:
"Two, two digit codes indicate the bottom and top colors respectively."
Covert Beige......50
Baroque Gold......57
Since 57 (gold) is your "top" code, I assume this means that it was the stripe color.
Hope this helps some!