I was searching for information on the Crosman 357/3357 myself when I found some pages with detailed photos from various angles.
Here is a page in german regarding the pellet gun 357 with many images Crosman 357
From the same page as above, very detailed pictures of various drums Trommelmagazine
This one is a since long gone sale add for a 3357 set. The images are still there though. Classifieds Airgun(Kitching): (All Sold Thanks) Crosman 3357 Paintball / Spot marker gun. $30.00 shipped to lower 48.