Thanks for posting those details. I note there is a date stamped on the lockcase. I have emailed the museum to see if someone could look at it and see exactly what date that is. I was there but cannot remember whether that lock was the Day & Newell design or had the Hart improvements. Anyone recall ?
I’m going to try and build a bit of a list of known locks here. Anyone with knowledge please jump in !
I think locks numbered in the 500’s were all Day & Newell design, and the 600’s all had the anti pressure - anyone know different ?