I read, certainly about Persian armour.
In the very first photo from a museum, too it seemed to me, that behind in the distance to the left a Bofors 75mm mountain gun.
In the center undoubtedly 37mm ATG Skoda mod.34 (3.7 cm ÚV vz. 34). On it a photo I could not define the third gun precisely yet. It is possible to tell precisely that it is a gun in calibre from 47 up to 65 mm, created approximately from 1890 till 1910, most likely firms Skoda or Krupp