The earliest fragments of the cartulary of Oberto Scriba de Mercato, dating from August 1179, present a picture that accords with diplomatic developments during the 1170s. The caution of the later contracts of Giovanni Scriba has evaporated; not just Genoese but Pisans, Luccans, Flemings and native regnicoli are shown working together in Sicilian trade, in the atmosphere of confidence generated by Barbarossa's withdrawal from Italy. This climate extended further afield too: the earliest fragments of Oberto's work show Lucchese cloth being sent to Ceuta, and, remarkably, a Pisan and a Genoese merchant agreeing to a joint venture to Sardinia, anciently disputed territory. It is, however, necessary to reserve judgement on some details of this material. Oberto provides solely a month's contracts – from 3 August to 5 September 1179 – and it would be meaningless to compare the total investment of merchants in different Mediterranean ports, and to deduce from these figures the proportionate rôle of Sicily and other markets in the overall trade of Genoa that year. (This will prove a recurring problem.) In August and early September 1179, Oberto registered nine contracts for Sicily, six for Sardinia, six for Ceuta, five for Bougie, five for Syria, four for Constantinople, one for Provence, one for the Maremma and one for Naples and the Maremma together. In the light of developments in the early 1160s, none of these destinations need occasion surprise.

The relative prominence of Sicily in August 1179 can be attributed to chance clustering – the tendency for a group of contracts for trade in the same convoy to be registered together.