Summary of manuscripts of Contra Celsum.
Roger Pearse, "Origen: the Manuscripts of 'Contra Celsum,'" tertullian.org, accessed July 13, 2023
Codex Vaticanus Graecus 386. Also contains the panegyric on Origen by Gregory Thaumaturgus, which is prefixed likewise to many of its copies...
In the 15th or 16th century a leaf had disappeared from Bk. 2, c. 13 ff. However as early as the 14th century, passages by Celsus had been erased. For example in Bk. 1, 32 a slander about the birth of Christ had been erased, perhaps as blasphemous.