Vis and Money (p.35)
The Covenant has a moderate store of both vis and silver.
100 Pounds (10 build points), mostly in silver coins, tin or bronze ingots, and jewelry. This is about equal to one year’s income, or one year’s expenditure.
But source of income isn’t defined in the document. Actually, it seems that it is up to you to define it. Sorry. Maybe s.o. could ask Tim Ferguson for?
Maybe a track (p.30 - about Tobias the Merchant…) :
In exchange they [the magi] provide him with money and offer cheap goods to sell in the coastal towns.
Maybe another track :
Covenant folks are sailors… maybe some are fishers?
Could arts and crafts, fishing and maybe breeding be the main Covenant sources of income?
This could be appearing sort of slavery to Covenant folks (plot hooks…). I don’t know. What do you think of this?
Another track again:
Maybe there’s also a (hidden/forgotten/haunted) copper mine – bronze is alloy of (large amount of) copper + (some) tin – on the island (see Asteria of Verditius's sheet) and it produces enough metal to be sold elsewhere? And what about a (secret/un-talked) little gold vein in it?
Don't hesitate to propose other tracks on this very thread!