Perhaps you could get a multimeter style casing and an appropriately satisfying needle dial and rig up a custom circuit board for inside it which would internally be much the same as light testing devices, and then provide an appropriate signal to the dial so as to have it follow the behaviour of the dial in the present aging meter.
I think you're talking about low voltage incandescent lights here? A circuit which put a sufficiently high voltage on the testing probes would likely do this, your dial could then be directly controleld by the amount of current flowing, just with the readings marked fof calirated for ohms given the known voltage. I doubt many modern multimeters would be applying voltages close to 12V to the probes in ohms mode, especially as such voltages would easily damage integrated circuits if used for continuity testing on anything involving 5V or 3V3 logic. A custom build might be the best option where the aesthetics of the device seem to be as key a part of its usage as the actual functionality.