What did Protestant reformers think about the date and authorship of the New Testament? Biblical scholars state that the different books of the New Testament were written between 49 and 120 AD, approximately. This means - rather uncontroversially - that the activity of the Church (i.e. of Apostles, converts, churches, etc) predates the Scripture.

Now, this Biblical research is fairly new, starting only in the XIX century. This is, by the time of the Reformation, such research was not available. Which was the opinion of Reformers on the origin, authorship, and dates of composition of the New Testament? Was it in line with the current scholarly research?

PS: Although I do not want to deviate the purpose of the question to other issues, my interest on this issue is the Sola Scriptura debate. Maybe Calvin and other reformers believed that the Scripture was not temporarily before the Church activity? (or, roughly speaking, that what the Catholic Church calls the Tradition did not come before the Holy Writ?)
There never was any argument between the Reformers and the Catholic church regarding the canon of scripture, just as they never had any difference of belief about the Trinity doctrine. Going back to Martin Luther, here is a quote from a historian:


  The Bible for him was not strictly identical with the Word of God. God's Word is the work of redemption in Christ which became concrete in Scripture as God in Christ became incarnate in the flesh; and as Christ by the incarnation was not denuded of human characteristics, so the Scripture as the medium of the Word was not divested of human limitations." (Here I Stand, p 331, Roland Bainton, Lion 1988)


He goes on to deal with Luther's translation of the New Testament into German, published in 1522. Although Luther had "a hierarchy of values within the New Testament", the existing canon was maintained and none of the Reformers disagreed with the ancient views of origin and authorship of those texts. Obviously, they had no knowledge of current scholarship, but given that none of the New Testament writings mention the fall of Jerusalem in A.D. 70 (though 'Revelation' might have been written after the event) it's unlikely they would support a post 100 date.

As for whether "the activity of the Church predates the Scripture", the first century Church certainly was active even before the first part of the New Testament began to be written. The book of Acts shows that the Church exploded on to the scene, with great power, only ten days after Jesus had returned to heaven. Thousands were converted in a very short space of time, yet note how those first Christians kept quoting from the ancient Hebrew Scriptures that were their only "Bible" up until the New Testament Scriptures began to circulate and be copied. Without the ancient Hebrew Scriptures, there could be no Christianity as Jesus was the fulfilment of its prophecies about a Messiah. All the new converts in the first century were converted on the basis of understanding how Jesus fulfilled the already existing Hebrew Scriptures. 

Your final query, whether the Catholic Tradition came before the Holy Writ or not - the Hebrew Scriptures came hundreds of years even before Jesus was born, so I assume you actually mean 'before the New Testament'. The Reformers regarded Scripture as the church's constitution which is (and I now quote from another history book):


  ...to directly counter the Roman Catholic claim that the church is the mother of Scripture. The canon, as the constitution of the church, is what constitutes a people as this people, under this government, in this body. Of course, the Reformers and their heirs never doubted that the church came before the completed canon of Scripture in history. However, they insisted that it is the word that always creates the church. ...The law and the promise were God's sacramental word (faith-creating means of grace) even before they were committed to the canon. As that word became inscripturated, the church itself found its proper constitution. ...The churches of the Reformation do not deny the ongoing authority of the church in its representative assemblies, but the key difference is this: whereas the Roman Catholic Church combines Scripture and tradition as one source of magisterial (i.e. ruling) authority, we confess that this belongs to Scripture alone, with tradition as ministerial (i.e. serving). Just as courts interpret the constitution, church courts interpret Scripture. This is why churches from the Reformation affirm the ecumenical creeds and subscribe to confessions and catechisms as communally valid interpretations of God's Word. Yet again, it must be emphasized that this authority does not arise from the church. It arises from the canon that the church seeks faithfully to interpret in dependence on the Spirit. ...The Reformers and their heirs recognized that there were many traditions in the apostolic church that were unwritten. In that era, believers were to follow the teaching and example of the apostles in both written and unwritten forms (2 Th 2:15; cf. 1Co 11:2; 2Th 3:6)... Therefore, the churches of the Reformation have received the Scriptures as the sole magisterial authority without disregarding the ministerial authority of church councils. (Pilgrim Theology pp 67-69, Michael Horton, Zondervan 2011)