Warren, this might be of interest i’m also a fan of those Chubb drop handles, and from what I’ve encountered their timeline might stretch longer than expected..
If you know for definite that the handles you have are matched to the plates with the older 57 St. Paul’s address, then alls probably right, as Tom said its then roughly down to the change to the new address in 1877.
But, it does seem that type of handle may have been used over some considerable time, as I have one from a much later SRD badged 128 Queen Victoria St from a building dated 1898. I also know of a building with several largish doors, all fitted with the same drops, also badged with 128 Queen Vic plates from 1897.
The version they fitted on the strongroom doors is a fair bit bigger and heavier at around 4 inches across. I’ve now lost count of the offers I’ve had for this big ‘Chubb door knocker’!
