Oliverius has completed the first 4 of his Mercere-requested Fire-bane rings. The crafting cost for each is 10 vis, plus the fee of 20 vis (as per mandated by Verditius house!). The cost for all four, therefore, is 120 vis. Oliverius would like his usual half in vis of account, and half in ignem vis so he can start on the next set of rings.
I'm putting out the math just to make sure I'm not getting any of it wrong.
Although he is not done at the beginning of the year, one season into 1141, Oliverius will be done with the second set of four Firebane rings that he is making for the Mercere. By the end of this process, Olvierius will be very appreciative of the Mercere as patrons, and completely frustrated and fed up with making repetitions of the same items.
He may refuse to mass produce items again. 
EDIT: I also cleaned up Oliverius's wiki page, split off two side-pages, one for his spells and lab texts, and another for the items he has on display in his studio as well as the enchanted item descriptions.