I wonder why it wasn't done then. If the editio typica of the NOM has the "and from the Son" phrase, then why the Greek version -- out of all the versions in the world -- should not have it? And another thing: what do you mean by "reverse translate"? Let me remind you that the Nicean-Constantinopolitan-Toledan Creed is not the Nicean-Constantinopolitan Creed (although it is based on it), just like the Nicean-Constantinopolitan Creed is not the Nicean Creed (although it is based on it).
Because as has been stated many times on this forum, though you missed it, the Latin Catholic Church has conceded the point that in Greek the Filioque is heretical.
"The Catholic Church acknowledges the conciliar, ecumenical, normative and irrevocable value, as expression of the one common faith of the Church and of all Christians, of the Symbol professed in Greek at Constantinople in 381 by the Second Ecumenical Council. No profession of faith peculiar to a particular liturgical tradition can contradict this expression of the faith taught and professed by the undivided Church.
On the basis of Jn 15:26, this Symbol confesses the Spirit “to ek tou PatroV ekporeuomenon” (“who takes his origin from the Father”). The Father alone is the principle without principle (arch anarcoV) of the two other persons of the Trinity, the sole source (phgh) of the Son and of the Holy Spirit. The Holy Spirit therefore takes his origin from the Father alone (ek monou tou PatroV) in a principal, proper and immediate manner.1
The Greek Fathers and the whole Christian Orient speak, in this regard, of the "Father's monarchy", and the Western tradition, following St Augustine, also confesses that the Holy Spirit takes his origin from the Father "principaliter", that is, as principle (De Trinitate XV, 25, 47, PL 42, 1094-1095). In this sense, therefore, the two traditions recognize that the "monarchy of the Father" implies that the Father is the sole Trinitarian Cause (Aitia) or principle (principium) of the Son and of the Holy Spirit.
This origin of the Holy Spirit from the Father alone as principle of the whole Trinity is called ekporeusiV by Greek tradition, following the Cappadocian Fathers. St Gregory of Nazianzus, the Theologian, in fact, characterizes the Spirit's relationship of origin from the Father by the proper term ekporeusiV, distinguishing it from that of procession (to proienai) which the Spirit has in common with the Son. "The Spirit is truly the Spirit proceeding (proion) from the Father, not by filiation, for it is not by generation, but by ekporeusiV (Discourse 39, 12, Sources chrétiennes 358, p. 175). Even if St Cyril of Alexandria happens at times to apply the verb ekporeusqai the Son's relationship of origin from the Father, he never uses it for the relationship of the Spirit to the Son (Cf. Commentary on St John, X, 2, PG 74, 910D; Ep 55, PG 77, 316 D, etc.). Even for St Cyril, the term ekporeusiV as distinct from the term "proceed" (proienai) can only characterize a relationship of origin to the principle without principle of the Trinity: the Father.
That is why the Orthodox Orient has always refused the formula to ek tou PatroV kai tou Uiou ekporeuomenon and the Catholic Church has refused the addition kai tou Uiou to the formula to ek tou PatroV ekporeuomenon in the Greek text of the Nicene-Constantinopolitan Symbol, even in its liturgical use by Latins."http://www.ewtn.com/library/CURIA/PCCUFILQ.HTM