Astra 600 first contract unknown holster mark

[justsomeguy]

Hello,
I picked up this pistol a while back and have had no luck identifying the ink mark on the inside flap of the holster it came with.
The holster looks old but it bares the commercial mark of Akah so I assume it was bought post war. However inside the flap the ink mark which looks like an H with a dot on top, dot on the bottom and one to the left looks more like a department or unit marking.

I'm hoping someone could shed some light on what it actually is.

Thanks,
T