Q: I understand that the permission to use a reading from the marriage lectionary applies not only to weddings celebrated at parish Sunday Masses in Ordinary Time and Christmastime but to the other days listed in 1-4 of the Table of Liturgical Days… yes?
A: No. Compare The Order of Celebrating Matrimony (OCM) paragraph 34 and OCM 56. The permission to substitute a reading from the marriage lectionary in OCM 34 applies only to the previous sentence, the one about celebrating a wedding during a parish Ordinary Time Sunday mass.
OCM 34 was written in 1991, and it was carried into the Ritual Mass for the Celebration of Marriage in the third edition of the Roman Missal in 2002 without the final paragraph. The new English translation of the OCM should probably have corrected 34 to match the missal. OCM 54 is correct. If you have a wedding on a day such as the Nativity of John the Baptist on June 24, all the readings come from the solemnity of John, and none from the wedding lectionary.