Hi,
If your camera has lugs, I seem to remember that Mamiya made a fitting to snap onto the lug that allowed you to fit any camera strap to a 330. This web address will take you to the older cameras section of the Mamiya user's forum.
Dead Link Removed
If the link doesn't work, go to mamiya.com and wade your way through the menus to the user's forum and click on older Mamiya Cameras.
This Mamiya-sponsored web site is a very deep resource for the older tlr cameras.These guys are REAL fans of the 330 and such. Leave a message there and someone will have a comprehensive answer for you.