Nachttresorkassette = Geldbombe

Again we are trying to translate something that does not exist as such everywhere in the world. A "Nachttresorkassette" is the formal term for "Geldbombe" which is only a small metal cashbox used by German retailers to make nightly cash deposits into a bank night deposit box/safe after the close of business for both the bank and the retailer. It would probably be better to use a somewhat longer but more explanatory translation because in many English language countries, a cloth bag or leather pouch is used for this purpose.

Duden Oxford shows "night-safe box". See the discussion under your question on "Geldbombe".

I'm not so wild about the term "night-safe box" without more explanation though because it could be confused with the box or safe itself in the outer wall of the bank.

Everyone knows what a cash box (two words is how NODE – The New Oxford Dictionary of English writes the term) is, so by using "night-deposit" or "night-safe" as modifiers (maybe with hyphens for clarity about what modifies what) in front of "cash box", you then also inform readers in countries where the bag or pouch is used how the thorough Germans do it.

HTH

Dan