I think both the tan and green layers could be original/pre-1945. Some sections are puzzling, such as the green paint which appears to sit on top of bare metal (specifically around the brim).
Note that Bulgarian Green is more Olivine in color than the paint on this helmet. It has what I call a Grass Green. Very much different tint.
"Much that once was, is lost. For none now live who remember it."
This bulgarian green was used after WW2 that's why its grass green.