my garage lock with a plexiglass side

[GWiens2001]

Those are not false gates.

Gordon

[supercat101]

Those are not false gates.

What is the purpose of the serrations if not to give the bolt a place it can pass a little ways into without allowing the bolt to move all the way?

[GWiens2001]

The bolt needs to travel farther than one single turn of the key can move it. Since multiple turns are needed, there are multiple notches.

False gates are most frequently cut into the levers, and the stump catches in them when the bolt is tensioned before the levers are at the correct height.

Gordon

[supercat101]

False gates are most frequently cut into the levers, and the stump catches in them when the bolt is tensioned before the levers are at the correct height.

Ah, I was referring to the picture above which you posted "wow id like to have a go at picking that". I think it was captioned as a kromer novum single-throw lock. That lock appears to have the bolt slide into gate slots in the levers (rather than moving from one part of the lever into another) and the levers have serrations on the front.

[kwoswalt99-]

wow id like to have a go at picking that

The regularity of the false gates would seem to facilitate impressioning, since it looks like the real gate is larger than the false ones. For each false-gate height, use a soft-topped blank to raise levers to that height, put the lock under tension, and wiggle the blank. Observing which heights cause each lever not to leave marks should make it clear what the height of each piece of the key would need to be.

Even with irregularly spaced false gates, they can still be impressioned.