Dib-dob is used as a generic term for foreign currency (I've come across it for Euros and Dollars).
I've recently heard this used by some RAF types, and had heard it before, from someone presumably influenced by family members in the Royal Navy. The Guardian has it as submariner's slang, though the naval influence when I heard it was shore-based and, I seem to recall, surface ships.
I don't know whether it's specifically UK military, or even whether it extends to the army (the RAF has some significant naval influences which may be surprising to those who haven't read its history). I can't find it in any dictionary I've tried online, and Google isn't being much help even with "-scout -scouts". Urban Dictionary does have a definition (for what it's worth), but a different one "A retarded child. A window licker. A boss eyed dribbler. A Currys or Comet staff member."
I've tried looking at the currencies of places where the Navy (and later RAF) might have been stationed, but haven't seen anything obvious. I'm interested to know where it came from and how long it's been around.