There’s a key element missing. These congregations, as a whole, have one set of beliefs, not the hundreds that are around today.
That's why I said, "but which organisationally is found in type in each local church body which truly stands on the Scriptures and the doctrine of Christ." If a body rejects the foundational truths which the Bible teaches about Christ, then it has no place to claim to be a church with Christ as its head.
My issue with Catholicism is not the general claim that if one dissents from true doctrine, then a church is not a true church. My issue is more particularly that Catholicism thinks of ITSELF as teaching the true doctrine, when an examination of the Bible says otherwise.
As for the hundreds (or thousands) of variant beliefs, well, do these beiefs relate to foundational matters of soteriology and holiness, or to lesser points of the law? In other words, some variance is not damnable heresy, while some is.