The helmet was built when I got it. However, I took it all apart, tweaked it to my liking, sprayed it, and assembled it the way I wanted. So yeah, I did it one piece at a time. It would be easier with a new bucket b/c you wouldn't have as many masking issues as I did since it wouldn't be cut out or dremeled yet.
Thanks for the compliment by the way. It did a little heft to the bucket as well.