For whatever reason I decided to lessen the rake (tilt) before listing them. After lowering the front spikes, and use of small wooden blocks below the back spikes, the speakers are (almost) perpendicular. In a note, it’s an entirely different, superior speaker.
We later concluded that my friend’s speakers worked because they were up against the wall. Consequently, being diapolar, the reflection off the front wall negated the ill effects of the ML’s 5% rake.