What do we call the handles, ornamental fixtures, and fittings attached to the casket shell?

The term used to describe the handles, ornamental fixtures, and fittings attached to the casket shell is "hardware." This terminology encompasses various functional and decorative elements that enhance both the functionality and aesthetic appeal of the casket. Hardware typically includes items such as handles that allow for easier transportation, as well as latches and hinges that secure the casket and add to its overall design.

Other options, while they may reference aspects related to a casket, do not specifically capture the full range of items described in the question as effectively as "hardware." Ornamentation refers more broadly to decorative elements but does not specifically denote the functional aspects associated with handles and fixtures. Decorative trim usually implies ornamental borders or edges, lacking the comprehensive meaning attached to hardware. Fittings could suggest components that are attached but do not fully embody the idea of all the elements, particularly the handles associated with caskets, as well as their dual role in both function and design. Thus, "hardware" is the most precise term for the diverse components referenced in the question.