If these are cockpit lights then they were wired into the plane, right? So you're talking about stationary not portable, right?
(For portable, you could always use 9 123s in series
)
For stationary you'll need a 28V power supply. 28V aircraft power is nominally 28V but varies, I suspect, not 100% sure--like a 12V car is really 14.4V. Since these are older items, perhaps you don't want to stress them all that much. I would suggest running them on 24 volts and they'll last a long time AND it will be easier to find a power supply.
You don't need regulation and you could run them off a 24V transformer--but since these are older, you might choose a regulated power supply.
How many watts of lights do you have here?
We might be able to find some power sources, etc. on a Web search, but if you browse through
www.mouser.com you should find both power supplies and transformers. I don't know if you're using a lot of light if you'll find the ones with the correct amperage, but a 5A supply should get you started (120W at 24V) for at least playing with these things. See if you can get SOME range of adjustment. Power One is a source of power supplies.
Cheers,
Richard