Keil New York Company, Super Safety "Pick Proof" Lock.
Not sure on the history of this lock, pretty sure I read somewhere that the company was sued for false statement, and was forced to stop labeling the lock as "Pick Proof". Either way the max depth first cut, mixed with the blocking disk and interlocking first pin, and free floating stacked disk driver pins make this lock pretty interesting to pick. Here are the pictures.

You can see the blocking disk right under the first key pin.

Expandable mortise cylinder

Plug with key pins, note the notch in the first key pin, and the disk it sits on.

How the key pin sits on the blocking disk.

The key with key pins, they are all the cool bomb style pins with the exception of the first pin and disk.

Driver pins are free floating disks stacked around a central rod. Note the first driver pin and first key pin interlock together.

Close up of the stacked disk driver pin.