To get more evenly distributed light, I guess one need to have thicker material of green?
With original green stuff light is running inside of green to produce more even glow afaik.
It however does look really good already, imo, even colour is not quite right yet, it looks like that it is more evenly distributed than with my white paper face plates.
Now your problem is that to get it perfect, you would need close to 1mm thick green, maybe water cutter project from odd bits lying around?

Volvo 360GL -88 -under restoration-
Volvo 343DL vario -81 -running-

Volvo 240 Diesel -83 -undecided-
Citroen ZX Dturbo -97 -daily-

