This entirely depends on what company / process you want to use to make the panel. If it’s stamped, machined or lasercut you should just be able to send the ai/pdf file to the fabricator (you probably want to ‘outline text’ in illustrator first).
You’d only want to put it into eagle if you want a PCB front panel. Doing this has become quite popular because small quantities are more accessibly priced, and PCB fabs have tighter tolerances than most metal manufacturers.