James Henley Thornwell in the 19th Century squared off against Charles Hodge in an extensive debate that started on the floor of the Presbyterian (Old School) General Assembly and spilled over later into the Princeton Review, the Watchman and Observer, and the Southern Presbyterian Review. Thornwell rejected Roman Baptism, while Charles Hodge accepted its validity.
Before that time, the general consensus of the Reformed Church was that the Roman Catholic Church had indeed become apostate, but was in some sense still a church. Antichrist was correctly identified as the Papacy by the Reformed Church, in part because the man of sin "sitteth in the temple of God, shewing himself that he is God" (2 Thess. 2.4).
(Both Thornwell and Hodge agreed that the Roman Papacy was Antichrist. The Westminster Confession's affirmation of this doctrine was not removed until 1903, when the Presbyterian Church in the United States of America (the Northern Presbyterian Church, or PCUSA) did so.)
Peru Mission was forced to address this issue because of its missionary efforts in Roman Catholic territories, and having investigated the question of whether re-baptism is required of converts from Catholicism, is to be commended for publishing the fruits of its research as The Reformed Churches and Roman Catholic Baptism: an Anthology of Principle Texts. I commend this work as a valuable resource for those who may wish to study the issue for themselves. It cites both pre- and post-Council of Trent Reformed writers who addressed and affirmed the validity of Roman baptism, addressing also the subject of the Roman mass, and Roman ordination, in the context of Rome as an apostate church which is yet a church materially considered. Those who wish to delve into these questions will do well to study this anthology.