What type of bulbs do they use? Do you know the voltage? (I can poke around Google later when I get a few spare moments.)
I have a Carver M-500t, which has the two large analog meters on the front. On the Carver forum I had inquired as to what type of bulb it uses, and someone sent me some bulbs pulled from some 1970s Japanese receivers. These are an 8-volt solder-in type that were all the rage back then.
The Carver is (thankfully) out of my system now, so I still have a few spare bulbs. If they are the same 8 volt type, I could get a few to you. Keep in mind that they are used bulbs, so they could last years, or just months. I had one of my meters' bulbs burn out again, but it could have been the opposite meter (the one with the original bulb from Carver--they are decades old and had daily use here). However, I don't know of anyone that sells new 8-volt bulbs--I don't think they are even made anymore. Hence, my getting the used bulbs.
For the Carver, I'm likely going to keep it for a non-critical system, but I do plan on recapping it and converting the meter bulbs to LED, as many have done. So I won't have any use for the bulbs. I just need to get a couple of warm white LEDs so I can match the original look. I'm surprised nobody makes some sort of conversion kit for these vintage receivers.