I have also just purchased what was advertised as an all brass 19th century prison lock…captured my attention because I noticed the faded Chubb emblem which I think is made out of copper…I can just make out that it says queen Victoria St etc.apparently it measures 13 cm by 13 cm and weighs 1.5 kg.. the number on the stopper ,is hard to read but as far as I can tell reads 1187007….again it’s missing the key and the knob? or handle…will post pics when it arrives ,suffice to say , ,,, I’m really excited to learn more about it…I will post some crude pics for now ,cos computers and I don’t get along that well lol.