P133 There is a possible textual variant that might have originally written in P133 that is no longer visible due to the flaking ink. If the Eta were there, it might not have been seen as part of the nomina sacra by later scribes who had not known the hymn, but rather as an incorrect and misplaced definite article that was an obvious scribal error and was so eliminated. This is the nomina sacra according to the P133 scribal copyist (though not originally) in 1 Tim 3:16 that is presumably ΠΝΙ, but might have originally been πνευματιη to satisfy the necessary meter of the original hymn, which might have been written as follows.
ὁμολογουμένως μέγα ἐστὶν τὸ τῆς εὐσεβείας μυστήριον θεὸς ἐφανερώθη ἐν σαρκί ἐδικαιώθη ἐν πνευματιη ὤφθη ἀγγέλοις, ἐκηρύχθη ἐν ἔθνεσιν, ἐπιστεύθη ἐν κόσμῳ, ἀνελήμφθη ἐν δόξῃ.
This alternate form appears to have been used by Aratus in his Διοσημεια as well. P133 needs to be photographed under ultaviolet to see if there are traces of the Greek Eta, which might have flaked off. There appears to possibly be too much space between the Iota of ΠΝΙ and the Omega of ωφθη. I think there might be a letter missing, and I think it might be Eta.