Unknown wooden ammo box

[Corneleijtens]

Found this wooden ammo box a couple of weeks ago.
Does someone know what kind of German ammo box this is? It’s marked 12 Bd Kg. 42 Gb.

[maksiusta]

30 Nb.Eihgr.42 (Nebel Ei handgranaten 42) should be present in this box. Its dimensions are 37 x 37 x 15 ?
It was probably reworked 12 Gw.B.Gr.42 (Gewehr-Blendgranaten) or Nb.K.S (NebelKerzen Schnell 39).

[Corneleijtens]

Already found this one. Dimensions are indeed 37x37x15.
Still can’t explain the text.

http://wehrmachts.kisten.free.fr/caisse_nbeihgr42.htm