Ann: Galena Updates Resource, Reserve & Mining Inventory, page-10

They seem to have been conservative , with a 5 meter wide minimum mining width so I infer they are not using single boom jumbos , however the 5% Pb cutoff average would be around US$96 a tonne currently which is about 2.4 grams Au equivalent per tonne.
I find it hard to imagine they could mine break even at 2.4 grams a tonne gold underground but then again they did state there was some room and pillar mining which is loer cost than long hole mining .