I have the same problem mate, i come across a lot of these without keys in my job. They work from the "fin" on the key instead on the notch in the middle of the centre. The only way your picks will work is if you remove the notch from the centre of your pick, and silver solder a precise kind of fin on the top/end of your pic in which to index the lock when turned. The idea is you cant get the pick back out till its back at 12:00. Ive been meaning to try it but i'm waiting till i get some cheaper southords, i dont wanna damage my hpcs.
Here's a better picture of the same kind of lock
glamour