American combination lock with key override

[bugefun]

I have an American Combination lock with key override, and I do not know the combination. It has the keyhole on the left of the back, and I'm fairly certain it opens on the right of the front (the same side as the keyhole.) It is the same as the two with keyholes in this video http://www.youtube.com/watch?v=9GQm3M5kzwU
I can't get it open in any way.
The hole around the right lock bar is really tight and hard to get a shim in. I tried going straight down the inside, the outside then turning counterclockwise like this video http://www.youtube.com/watch?v=cj_VR0_l1_Y , and the outside then turning clockwise. When using pliers to turn it clockwise a piece broke off the shim and stayed inside the lock. The shim was ripping when turning the other direction also, but I stopped in time.
I tried picking it, and like the first video showed, turning the plug clockwise. I think I got all the pins down, but it will not turn. Do I need to also push or pull on the loop? Did the piece of the shim permanently break the lock?

[Altashot]

If you have the cylinder in the back picked and turned all the way, it should open. I suspect the shim stuck in it is binding the shakle. You may need to pull very hard on it to release it.
I do not believe it would have broken it though.

Max