One way you can make the generic box "non" generic is to create a printed/laminated overlay that slips (and velcro's on) over the buttons and switches.
This overlay will indicate what the buttons do for each specific aircraft. (for example, a one engine aircraft wont have a "L" and "R" engine starter switches)
Then create a different overlay for each aircraft. So when you change planes, just rip off that overlay and slip on the appropriate one.
Can easily be achieved using a printer, a metal ruler and a sharp razor. Velcro is optional. Laminator is optional. Perhaps a "matte finishing" spray from your local art store to reduce reflection.
