Something tells me that the devs will never, ever make this currency-system work with HnH. In a recent thread jorb shed light on why he is against coin-based trading. Many of us disagree with him, but from what I've heard, community-fueled ideas like this have been around since world 1. I just wonder, jorb, why coins got implemented in the first place if there is no way to print them. Care to comment?
The problem with Buyan Market, for example, was this: I went there with 6000 selfmade bronze coins and literally bought the place. Tin and copper were quickly mined, smelting 60 bars was not a hard task, and it was highly rewarding. Afterwards, my town was littered with chests filled to the brim with delicious dwarven goods. And what about Buyan?
Its stand owners were probably baffled when they discovered the insane amount of metals they had earned, but it was actually useless (except for repairs) and didn't require significantly less work to smelt it back than it would've taken to mine in the first place.
So, no matter what kind of unprinted coin-based stands you set up, as long as printing coins doesn't get implemented, vending stands will be useless
tl;dr
Devs, it would be a good idea to either implement coin branding or remove coins altogether. Right now coins have no use at all.