Wow! Stickied! This is my first!
Anyway, the putrid fiberglass smell can be a bit overwhelming... when I first got my Red guard helmet for example, I thought someone had pissed into it previously. In the case of this Vader lid, what I did was once the painting was completed, I fixed my electricals (two fans) on the inside and covered the wires as well as the entire inside of the helmet with foam padding, the type you can get at any haberdashery. I was fortunate to find the black colored variety instead of the typical beige one so it suited the Vader lid. Its very comfortable and to be honest, I can't smell the fiberglass at all. I'll take some pics tonight and post them.
On my Red Guard helmet, I didn't pad the inside as it was already claustrophobic as it it, adding padding would make it even worse. So what I did was wash the insides with scrubbing brush (the gentle variety, not the steel wool!) and a pleasant smelling soap. After a few wash, the smell is not as bad. But make sure you wash with hot water (but not boiling), they tend to get rid of the smell better.
Oh, and to answer the earlier question, I'm about 450 km north of the Causeway

... in KL.