As mentioned on the Facebook page, I agree that it is a very early Mosler Screw Door. It would be from before 1890. Look closely for a serial number on the body, door pivot finial, or on a hinge finial. It could possibly be stamped on the small gear also. Terry posted a picture of one. I will add it here for fellow members. Yours has the dial which may be correct. Take detailed pictures of it.

There are three other clues that tell me it is a Mosler. They are a pivot mount, time lock linkage spring, and the pattern of the bolt holes for the time lock shown in your picture. Mosler screw doors used the Yale Triple L time lock of a specific version. Your door is set up for that.

Never say never on parts. One of my Mosler Screw Doors had the time lock missing along with all the linkage. I found a parts safe in Florida and got all the parts I needed.


I had to do some digging but knew I had it somewhere. This is an early model Model Screw Door but in the double door version. Extremely rare. I would consider your safe rare too. Picture provided by Doug MacQueen.
