No server, but I have economy ideas for you:
In Eco, "backed currencies" are not backed currencies because you cannot retrieve the resources used. These resources are destroyed. And It has no sense to destroy resources and waste calories and time to facilitate exchanges on your world!
If you want a real backed currency, you can open a bank with stockpiles and a store with "1 resource = 1 coin" and "1 coin = 1 resource". The coin is a "backed currency", and for the resource to destroy you can choose the less caloric renewable resource of the game : arrow. You have to create coins as much as you can stock the chosen resource at the bank, and give all the coin to the bank.
Now, when you sell something for coins, you know that, for any coins you have, resources are waiting for you in the bank :)
You can also do this using the credit currency of the player owning the bank, but he must not spend more credit that "resources at the bank - credit in circulation", so he has to put resources himself at the bank.
You can also try a new paradigm of money as described in the Relative Theory of Money: money must not be a store of value.
Create 1000 coins (using "backed currency" with a less caloric resources like arrow) for each player and new players on your server, and 2 laws:
the first tax 10% on each player every day
the second distribute an universal dividend of 100 coins to each player every day
Fun fact: if you have 1000 coins, the taxe is 100 coins, so with your universal dividend you remains at 1000 coins.
So you lose money only if you have more than average, and gain money if you have less than average :)
You can chose a different tax rate (or average), but the universal dividend must be the average time the tax rate. For example, if you want an average of 2000 coins per player and a tax of 15%, the universal dividend must be 2000*15%=300.
You can also choose to do this not every day but every 2 days, or every hour (with a smaller tax of course!).
If you have questions, do not hesitate!