Macula@Markusius ah.. I mean if you widen the light hole, it will fit over the stub head on the energon ver. The stub head is the same width as the white cam piece inside the G1 head.
I'm surprised nobody has modelled the encore mask for the 1 head!
Macula If you enlarged the hole at the bottom, you could have it slip over the existing stub head, letting you swap back and forth as needed (minimal modding)
I actually milled out the hole in the bottom of a g1 head, to get the same effect!