I ran into another one of these today. Twenty year old 1" Baldwin mortise cylinders with Baldwin stamped into the face on the entrance to a home with standard Schlage locks on the rest of the house. Use the Schlage pinning chart minus .005 to pin the mortise cylinders when using standard Schlage blanks.
Schlage: .165, .180, .195, .210, .225, .240, .255, .270, .285, .300
Older Baldwin mortise cylinders and maybe some new ones are:
.160, .175, .190, .205, .220, .235, .250, .265, .280, .295.
Some newer Baldwin mortise cylinders and all the dead bolt and key in knob lock cylinders that I have seen are standard Schlage.
It is possible to insert the plug of a Baldwin mortise cylinder into the shell with the longer pins installed into the plug before snapping to the problem, letting the bottom pins jam into the upper pin chamber of the shell after removing and reinserting the key. The key will not let the bottom pins fall far enough to clear the shear line after reinsertting the key to turn the lock plug.
Once that happens either file the key down .005, pick, or shim the cylinder to solve the problem.
Hope this helps.