Summary: If you want a more sane solution, as I'd prefer, remove the optional PB-E2 Booster Grip as shown here, and replace the grip with the standard one that shipped with the EOS 3. When you do this, the EOS 3 becomes a much more manageable camera.
Excerpt: The advances in still, film-based cameras
are coming in increments. The essential shapes and functions are now well
known. As we begin what may be the last developments in film cameras, the
purpose of the manufacturer (other than selling cameras) is to refine the
capabilities of the equipment. The photographer is the big winner. Prices
are coming down--functionality is going up.