Thank you Juan!
a SE sandy eh? That will be awesome! I dont think there are any currently, so I am sure it would be thrilling to be one of the first!
As for the frown, yes I masked it off using painters pin striping tape. You can buy some of this tape at hobby stores and possibly specialty paint shops. I also painted the frown using a quality synthetic brush, not spray paint.
It took me awhile to get the frown right, I looked at A LOT of images of the original ROTJ helmets and carefully plotted out where to mask it off. If there was anything I was more concerned about with the build, it was surely the frown.
I also used a blend of two different paint finishes. Both paints were the same brand and color, except one was matte and the other semi-gloss. I mixed equal amounts together to form a sheen which was more so a "correct" satin finish. Of course in the photos the black paint looks a bit like semi-gloss due to the flash and all, but in reality it looks dull. I also suggest that even if the black is to shiny, dont go over it with a matte paint, just use a deglosser (liquid which removes sheen off a paint surface) or fine sand paper to scuff out the sheen. It would look much more realistic!
Also, the first time I painted the frown, it looked like ****. I did not sand down the paint job, but applied a paint stripper which was safe on plastic. It worked very well, but took A LONG time to work into the paint. I would suggest picking up some of that! I believe it is made by testors..again that too should be found also at a hobby shop!
Good luck man!