Just tested it and it seems to be working fine for me - im guessing its not clear enough how its supposed to be used (The 'Ancient' blacksmith is not like the traditional production buildings you're probably used to - and its also missing a bit of functionality for the building's owner).
The way that script was done.. First, you must set sell prices for the various items. Next you need to have a blacksmith employed (they get 1 gold per item produced). Then you (or someone else, if you've set a buy price) puts iron in the building. You now have a functional blacksmith.
To actually make items, players must have enough gold to purchase an item.. if they do, they have the option to get the blacksmith to make one. Clicking the 'Make item' button takes their gold, pays the employee (any remaining amount is added to the building's profits) and then the 'customer' gets the item. (It appears atm the owner of the building doesn't get an option to actually be a 'customer' themselves, which is something i'll change tonight, and which will probably help explain how the building should be used).