Inflating a country's currency is one way to spend beyond your means. Then you revalue (or reset) the currency's value and start over again after confiscating value from those citizens who were wise enough to save rather than borrow. The US currency is due for a reset one of these years. The Fed states their target is 2% inflation, not zero inflation. So far, we haven't had run-away inflation as some other countries have had (Chile as an example in our hemisphere). Even so, the US$ lost 95% of it's value in the last hundred years.

I have seen overstamped and modified casino plaques, as you show, from several SA countries. It does give a casino a way to continue to offer gambling with the new currency without waiting for production of chips and plaques in the replacement currency. Put the night shift to work with a hot die and a knife and the next morning you are updated!

Of course, both Germany and France have seen new paper currency replace old; their casinos also had to resort to quick-changes to their chips and plaques.

Not very pretty, but the practice does give us collectors some additional pieces to collect.