I never really left. I've just had this project on one of my many backburners for a while. It's starting to look like it'll be a while before I get back to work though, so I'm dusting some things off and putting them back on my to-do list.
Regarding the RC helmet: I haven't measured it, but it's a bit on the big side. For the dome I used a kid-sized skateboarding helmet. When you take all of the padding out, there's a lot of room in there. Sooner than later I'll get that one rolling again too.
Then I'll start on the rest of the RC armor about the same time I start building my vacforming machine...