Thanks for these dates Paul.

I wrote a reply earlier, but seems it's disappeared into the ether. Good to have some pretty close manufacture dates
Brian has also said he'll provide whatever the Museum holds.

I'd not realized lock 1169015 falls in the 19th century. It's a few decades older than I thought. A little unusual to me as it has a tiny keyway. I've not come across many like that.

Re lock 1891, it appears rather old. You mentioned it's the 1824 Patent. Am I right that that was Chubb's second patent, and otherwise known as the 'Improved Patent'?

The key operated the lock, and resets the Detector.


Any idea what the U stamped on the plaque indicates?

Thanks again