Quote Originally Posted by YALE7750 View Post
I have a couple of cylinders clearly marked Schroder that are the conventional pin tumbler type. Keys are 6 pin nickel silver, D keyway, (2632GD for the Graham sectional blank) with what I assume is the key code in letters stamped into one side, much like an Eagle key code. The funny thing is the cylinder itself has an entirely different key code stamped on the back of the cylinder in numbers. Searching on the Internet turns up no info about these. Apparently the only pictures are of a few that have shown up on eBay, nothing else. I’m going to assume they were not produced for very long just based on their apparent scarcity and the absence of info about them.
There is scant information on J.B. Schroeder & Co, however it appears they were established in 1834 and I see evidence that they were in business as late as 1922. I'm guessing that like many manufactures of the era that they may have failed during the great depression which began in 1929. Multiplex (sectional) keyways were first introduced and patented by Yale in 1896. Again, I'm guessing your cylinders may date to c.1920.

Pete Schifferli