While troubleshooting an igniter problem, I noticed that the bottom of the burner tray is VERY rusty and that 3 out of the burners do not sit horizontally, because the back bracket completely crumbled (so the far end of the burner dropped.) I ordered the igniter before thoroughly looking at the unit, but now I am thinking it might be time to replace. I can probably fabricate a back bracket if I can figure out how to access the back of the unit. The unit functioned well so far and the burners look totally fine.
And advice would be greatly appreciated.