My mantis had lost one of her smashers before I bought her at the LFS (I was aware of it, but hoped she'd recover). She had totally regrown the appendage within 4 months, couldn't tell it had ever been gone!
I feel like a bad mantis owner though--I NEVER know when my mantis molts. She's out every day, unless she's targeting my days out of town to molt. How long does it take a peacock to molt and how long should she be in hiding with one?