As far as the stencils go, as you mentioned there's going to be some small amount
of shifting necessary to get everything to line up correctly.
Just think about how the shapes of the continents look on a flat Mercator-type map
of the world compared to their shapes on a globe.
Rafal has done an incredible job with his templates, but when you place them onto the
curved surface of the helmet, it's important to check against reference pics to get the
placement and proportions correct.
One thing I've done in the past is to actually measure a certain part of the helmet, say
one of the back panels, and make a plain paper template. I'll hold that piece of paper
up against my computer screen and compare it to Rafal's template. I'll use my graphics
program (I use PaintShop Pro) to resize Rafal's template until it matches. I have found that
it may be necessary to scale the vertical size and the horizontal size slightly differently to
make things fit. Like maybe scaling the horizontal to 97% versus scaling the vertical to 94%.
Something like that.
Granted, it's trickier to do this with the dome, but careful checking against the reference
pics will help with getting everything into the right position.