e ("Codex Palatinus") is a 5th century manuscript containing ONLY portions of the four Gospels (no Catholic Epistles and, hence, no 1 John and no Comma). Of particular note for our purposes is that it is an African version of the Old Latin Text, fairly much like what Bishop Augustine of Hippo used; it has, however, a significant number of later editorial changes which were applied in an attempt to make the text more similar to the
European version of the Old Latin Text.
a ("Codex Vercellensis") is a late 4th century manuscript containing the Gospels (again, no Catholic Epistles and, hence, no 1 John and no Comma) which, as tradition has it, was written in 370 by St. Eusebius, Bishop of Vercelli -- a tradition which is often doubted, though it may reflect that it was commissioned by St. Eusebius of Vercelli. It is a European version of the Old Latin Text and, hence, varies rather widely, at points, from e. They, together, could not be the basis of a general consensus (at least, not as far as I can tell).
p ("Codex Perpinianensis") is a 13th century manuscript made up of a mixed Vulgate in the Gospels and Pauline Epistles and European Old Latin in the Acts and the Catholic Epistles. Please note ... while p DOES contain the Comma, and thus 1st John, and while the Old Latin text IS European in character (the same as a), p and a are otherwise entirely dissimilar -- even down to which canonical works each contains. There is, therefore, no way they could possibly be used together to represent a "consensus."
r ("Codex Rodensis") is a 10th century manuscript of mostly a Vulgate Latin Text, with African Old Latin variant readings in the Acts found mostly in the margin but sometimes inserted into the text. The Catholic Epistles are NOT Old Latin (they are Vulgate) and, indeed, don't contain the Comma. Where the Old Latin marginal and textual additions in the Acts overlaps p's readings in the Acts, they MIGHT be said to reflect a consensus reading ... however, since the Old Latin notes are African text in character and not European, the possibility that they reflect or may be used as the basis for a consensus reading is practically nonexistent.
;)