The fiberglass shell turned out a little thin even after two coats. However, it's still very sturdy and should do it's job.
I'm really impressed by silicone now. After hearing a few mold horror stories I was a little concerned throughout the process but was put to ease when demolding. On close inspection there were no air bubble or even blemishes, my main concern. It turned out nicely and all I would need to do was a little trim work.
Up next: The first cast!