A major critical edition of the Old Latin is underway under the auspices of the Vetus Latina Institute. Some volumes have already been released. But, others are still forthcoming.
Meanwhile, the only complete edition of the Old Latin remains that published by Pierre Sabatier (Reims: 1739–1749).1. A later version of this edition, with some volumes reissued in later years, seems to have had three volumes, all of which are available on Internet Archive:
Of course, if there are additional volumes that I have missed, comments identifying those volumes and links to them (if they have been made available online) are most welcome.