Not a Chubb safe.
I believe the safe to be a Phillips & Son. Its key escutcheon may say inviolable or, if a Chubb lock, it will state Chubb Patent Lock
Missing plate shows the oval shield with lions and harp. Holding it up will be the Lion rampant (On 2 legs) with Unicorn.
I may have the odd one laying around.
Regards
Russell