Not sure if there is a part number for the leather itself, but any automotive upholsterer should be able to fix the seats. Our cat, for example, loves the leather. If we ever sell our Vectra, might have to fix them. Or, sell the coach, as 'cat approved'~!
We needed information about the passenger seat and a call to Winnebago confirmed it was not Flexsteel but another brand the name of which I can't remember. For our seats covered in leather, the manufacturer provided the seat to Winnebago and Winnebago upholstered it.