“It came from a toy store or a thrift store.”
Wrong
Correction
A magic and novelty shop on Hollywood Boulevard.
Carpenter names "Bert Wheeler's magic shop on Hollywood Boulevard, which was right up the street from our offices." Wallace called it "this large novelty shop" on the Boulevard. Shatner's "they found it somewhere in a toy store or somewhere" is his retelling, not an account.
What people actually said
“So the art director went up to Bert Wheeler's magic shop on Hollywood Boulevard, which was right up the street from our offices, and he got two masks.”