Another Old Yale

[kwoswalt99-]

That could be one of the warded lever locks.

Gordon

Is that possible with the configuration of the keyway? Maybe I've just never seen one.

here is one like it from macgng's collection:

That just looks like a warded lock. I will have to do research for patents or something. If these have levers in them that would be a big surprise. The key has varied depths of cut so I guess it's possible, but now I'm wondering how such a mechanism would work.

[kwoswalt99-]

I just looked through an old yale catalog, and I stand corrected. I was very surprised to see that some of these padlocks do have very small levers in them. The ones I have are purely warded though. The catalog was the no. 26 and had cutaway pictures. I would put a link but it takes too long to download. In this case impressioning would be different than in the link I posted. I think you would have to file down gradually like in a pin tumbler, but don't file the tip like billdesrthills said. I wonder how difficult this would be?