It looks like what i’ll need to do is look at a customized menu walker, as suggested at this thread over on Stack Overflow:
https://stackoverflow.com/questions/9003918/editting-wp-nav-menu-so-it-prints-divs-instead-of-lis
From there, looking at suggestions I found:
http://www.mattvarone.com/wordpress/cleaner-output-for-wp_nav_menu/
That’s solved this perfectly!