I would do this emissive, but using a specific map rather than just a value, I don’t think you can just rely on the colour map to do all the work
I would make a simple greyscale emissive map, brighter in the middle than at the edges (you can sort of see where the light is showing through in the photos), the key would be to then multiply it by the colour channel before connecting it up to emissive - they used to print movie posters on both sides so the colours looked richer when backlit