In the historic Western rite, it is the norm to have only two readings at Mass. The first reading may be from the OT, the Epistles, the Acts of the Apostles or the Revelation. The use of three readings, as is common today, is derived from the Masses of the Ember Days. The Ember Days are the historic days for ordinations; therefore, additional readings were included in these Masses.
I agree with Fr. Eckardt that Piepkorn's declaration that the first reading must always be called "the Epistle" is confusing. This is also at odds with the historic rite. Unless the reading is from the epistles, it is referred to as a reading or lesson.
The OT/Epistle is read by the sub-deacon. Before reading, the sub-deacon receives a blessing from the celebrant. Unlike the deacon at the Gospel, the sub-deacon does not request a blessing. The celebrant, without saying anything, blesses the sub-deacon with the sigh of the cross.