HopeOfTheFuture: those are some cool pictures. That one is the same as gizmo posted earlier in the thread. At first I would have pegged it as an M1 because of the two dots on the left cheek side under the temple, but it has later been shown that it is something else. Notice the circle detail in the front cover is similar to how it initially was on the sculpt, before it turned into the version seen on the production skulls. So it could be argued that it is pre-production style.
Did you remove the original detail casting in the temple and replace it with the model kit piece originally used, or is that how it was on your casting?
Hi leonuk: it is okay to ask those things in this thread, but would prefer you start a new thread if you show print and progress, though you are free to link to it here as what you do may be of great use to others making arms or full endoskeletons.