A genuine panel from an Airbus uses 5v bulbs for the backlighting. An original panel for a cockpit project will most likely come from an Aircraft which is over 15-20 years old. It is not unusual for panels from torn down aircraft to have blown bulbs.
When I received the overhead Fire panel more than half the bulbs were completely blown. Replacement of these bulbs did not lead to a satisfactory backlighting — you soon find out the new bulbs overshadow the old bulbs creating a backlight imbalance. Maintenance of the panel will require the replacement of all bulbs.
The Firepanel backlight board has over 30 bulbs — these were all painstakingly replaced by manual soldering. If you are refurbishing panels, you realize you will need hundreds of bulbs if you intend to replace all of them.
Fortunately our friend Holt has pointed out an affordable place to purchase bulbs — memotronics.com – a box of 10 #7152 miniature bead grain wheat bulbs 5v will set you back 5.49 USD.
With traditional bulbs you will require a high level of current to operate. The Fire panel itself requires 3.8 Amps (!).
The end result, well worth the effort: