I thought I'd add a note for the construction of the Boushh lid. Just the way I envisioned it when I designed the model and templates.
Build the main helmet all as one piece, then you'll be left with things like the ears, snout pieces and sensor that sits above the visor.
Build these parts and glue them into position on the main lid.
Now you'll have hollow areas inside these parts that you won't be able to access when fibreglassing. 
Not to worry, I encountered this problem when building my custom gauntlets. You need to carefully mark out where these pieces are on the inside of the lid. So you'll have a pencil outline showing you where to cut. 
The card should be thin enough to allow light to pass through and give you a general idea of where to mark these areas out.
Using a sharp, fresh blade on your knife, gently cut out the un-needed card from the main helmet where you marked out earlier.
If you've taken your time and got it right, you'll now have access to the pieces(ears, sensor above visor, and snout) when you come to fibreglass. Any excess card remaining can carefully be trimmed away first.
Anyone who's tried to build be Pepakura Fett gauntlets will have encountered this when building them and may have come up with this solution themselves or an alternative.
As I said, this is what I did for me Custom Gauntlets and it worked a treat. Providing you use plenty of glue to secure the parts and wait long enough for the to dry fully and set.
I know this may come a little late for some - Sorry McKenic - but I hope that it will prove useful for fixes or new builders.
McKenic, I think your lid can be fixed buddy. Too much filler is a pain but not the end of the world mate. You know how to reach me if I can help more.
