My understanding is that the Lord's Prayer was left untouched because it is so well known and recognized by all Catholics and many Protestants in its present form. For that reason, they even decided to leave in the "thy" and "thine," even though English vernacular "your" is used everywhere else.
That is interesting. With such reasoning, much of the remainder of the Liturgy should have been left untouched because it was so well known.

I have been reading some materials, including Fr Serge's informative book and The Divine Liturgy of some Orthodox Churches, and it my understanding that "debts" and "debtors" is the more accurate "Catholic" translation.