Complex sentence: We also have documentation of the body of St. Roch of Montpellier present in Voghera in 1469 and it being venerated since at least then; and of a feast in his honor being celebrated in 1483 in the presence of his remains.
Split into simpler sentences: We also have documentation that the body of St. Roch of Montpellier was in Voghera in 1469 and that it has been venerated since at least then. There is also indications of a feast in his honor being celebrated in 1483 in the presence of his remains.