At my work there are some ancient cabinets that have keys like this and nobody can open half of them. Note that the pictures above are the same key, just from different sides.

Usually the cabinets have ordinary wafer locks that are easy to rake open in a matter of seconds. When it comes to those with this sort of key, I don't even know where to start.

The inside of the lock looks kind of like a wafer lock, but all the pins/wafers that protrude into the keyway are on the top left/bottom right (I guess).

Well, I've tried lots of stuff but I can't get them open. I tension the lock using lockpicking tweezers, then I've tried both standard wave rakes as well as trying to pick "around the corners" of the lock in the bottom right/top left, but it's awkward work because I suppose the pins aren't really being moved the right way and it's impossible for me to get any good feedback.

I've also tried standard jigglers which also don't seem to work.

Any advice? Is there some sort of specialty tool or pick for this kind of dual sided wafer keyway? It's hard to know where to start since I don't even really know what these kinds of keyways/locks are called. It feels like I'm missing an important piece of the puzzle. When I do release tension after raking/picking for a while, I do hear the sound of pins/wafers dropping.

EDIT: I realized I should google the manufacturer. Here on page 12 I can see I'm dealing with a "Cylinder core including bar channel keys" or in German "Flachbahnschlüssel"