If one says Compline, and wishes to add Compline of Our Lady (from her Little Office), does one first say the Marian anthem &c. at the end of Compline, and then add Compline de Beata, or does one interpolate the latter after the blessing and before the Marian anthem?
I came to think this may be the case because Compline of the Little Office, when given as an appendix in a Breviary, was given with neither a final blessing nor Marian anthem until the 1962 edition – yet did appear with such when printed as a standalone devotion. This made me surmise that when the two Complines were said one after the other, the blessing and Marian anthem of the daily Office supplied for its little sibling as well. It would certainly seem strange, strictly following the '62 rules, to sing Salve Regina twice in close succession...
I recently found that in the Carmelite Breviary, the following rubric appears after the blessing: Statim dicitur Completorium de beata Virgine, si dicendum sit, quo dicto (vel si dicendum non sit) data benedictione, statim dicitur Antiphona Salve Regina... [It would appear to me that the second parenthesis is misplaced, and should have been after benedictione.]
Therefore, at least in the Carmelite Rite, Our Lady's Compline is interpolated between Compline of the day and the Marian anthem following.
However, the Roman and other Breviaries make no such note, and indeed have a seemingly contrary rubric to the effect that, after the Benedicamus Domino, Fidelium animæ is not said, but rather the blessing and Marian anthem follow immediately.