Corriente is one of those American breeds that descends from Iberian cattle that were brought to the Americas during colonization. It is used in Rodeo fights, among other purposes. Corriente is said to be a small breed and is phenotypically diverse, especially concerning their colour. A number of members of that breed has surprisingly aurochs-like proportions and body shape, even with a well-developed hump. I think Lidia may be among the cattle this breed descended from. Within the bandwidth of colours in Corriente, there clearly is the potential to breed a perfectly aurochs-coloured strain. Also the horns of some individuals are pretty good. In my opinion, a breeding project using well-selected Corriente and supplying them with breeds that add what is needed would create a herd that resembles the aurochs to a large extent. This would increase the genetic diversity for a metapopulation of aurochs-like herds all around Europe.
Here you have a collection of photos showing aurochs-like Corriente: