After skimming through this discussion, I’d like to offer some general comments about church history and Luther. There's a very good chance that if someone responds, I won't get to it for a while.

In regard to the use of the “Fathers,” I recommend, A Treatise on the Right Use of the Fathers in the Decision of Controversies Existing at This Day in Religion by John Daillé (Philadelphia: Presbyterian Board of Publication, 1856). I have not come across any of today’s Roman apologists dealing with the content of this book (if someone knows of any current defender of Rome dealing with Daillé’s argumentation, please PM me). The book is an eye opener in terms of assumptions about the existing record of church history and the use of the Fathers in establishing doctrine. After reading Daillé carefully, one comes to realize the danger in using any historical period as an historical norm. The Roman church today does not believe the same things that the church of the early centuries did. Simply look for some of the key teachings of the current Roman church in the early church: indulgences, purgatory, the absolute primacy of the Roman papacy, Mary’s bodily assumption, and even such a thing taken for granted as the correct number of sacraments, and one quickly realizes that something isn’t quite right when one of Rome’s apologists presumes that the early church is the property of Rome. Some of Rome’s best scholars realize the lack of unanimous consent among the fathers in regard to basic scriptural interpretation:

When one hears today the call for a return to a patristic interpretation of Scripture, there is often latent in it a recollection of Church documents that spoke at times of the ‘unanimous consent of the Fathers’ as the guide for biblical interpretation. But just what this would entail is far from clear. For, as already mentioned, there were Church Fathers who did use a form of the historical-critical method, suited to their own day, and advocated a literal interpretation of Scripture, not the allegorical. But not all did so. Yet there was no uniform or monolithic patristic interpretation, either in the Greek Church of the East, Alexandrian or Antiochene, or in the Latin Church of the West. No one can ever tell us where such a “unanimous consent of the fathers” is to be found, and Pius XII finally thought it pertinent to call attention to the fact that there are but few texts whose sense has been defined by the authority of the Church, “nor are those more numerous about which the teaching of the Holy Fathers is unanimous.” Joseph A. Fitzmyer, Scripture, The Soul of Theology (New York: Paulist Press, 1994), p. 70.
All periods of church history show continuity and discontinuity of periods that came before it. Of course there is an historical development in church doctrine and church practice… but how does one determine what has correctly… developed? History (and development) therefore is not an infallible standard by which to determine doctrine. More cautious Roman apologists realize this, which is why they typically argue that some sort of infallible sifter and determiner is required (which they claim to have). There is though a severe problem of double standards when Rome’s defenders pontificate. A Roman apologist will simply assume for instance that Trent was following the tradition of the church that there was no teaching of “faith alone” previous to Luther. Such an apologist will usually argue that Luther invented it. It didn’t exist until Luther. It can’t be verified in church history. It can’t be true. On the other hand, when the same historical standard is applied to certain Roman Catholic dogmas, like Mary’s Bodily Assumption, Purgatory, Indulgences, etc., this same historical standard is swept under the rug and hidden. One has to seriously question why a standard that Roman apologists hold Protestants to is not likewise applied to their own beliefs. Wade through the corridors of church history and search for the threads of all Roman Catholic dogma. One falls flat of linking many of them back to the early church, or in some instances, even the Bible.

As I’ve read Luther, he likewise doesn’t appear to me to think any period of church history should function as infallibly normative either. Since history is a beast in flux, Luther strove to direct the church to an infallible standard by which to evaluate doctrine, practice, and development. Lo and behold, the Christian faith has just that: the infallible words of God recorded in Sacred Scripture.

If one studies the early period of Luther’s conflicts with Rome’s defenders, it becomes quite comical: They quote this or that father or council and Luther responds back with Sacred infallible Scripture. David Bagchi showed quite convincingly that Luther's earliest Roman opponents failed in their efforts against him because while Luther argued primarily with Scripture, his detractors used a different approach:

...[T]hey relied excessively on the early fathers and lacked any doctrine of doctrinal development that would have helped them explain the accretions in practice and belief of the medieval church. They were too ready to contradict the reformers on the basis of established authorities rather than engaging the issues with any seriousness" (Luther's Earliest Opponents, p. 9-10).
Now Augustine in relation to Luther has been mentioned many times throughout this discussion. Certainly Luther held Augustine in high regard, but anyone taking the time to actually read Luther notices that his appeal to him is only occasional and qualified. In fact Augustine is treated like many of the other voices from earlier church history by Luther: he held his opinion could not be unquestionably followed, thus he commends him at times, and criticizes him as well. Since Luther’s infallible standard was Sacred Scripture, he did not cite or refer to Augustine or anyone to establish any doctrine. Certainly he would appeal to church history at times for polemical purposes, like when someone agreed with some particular point he was arguing, but for Luther, the church must always appeal to Scripture to determine truth.

“I cannot tolerate their [read: Roman apologists] slandering and blaspheming Scripture and the holy fathers. They accuse Scripture of being obscure, although all the fathers attribute the brightest light to it and draw from it, as David says in Psalm 119[:105], “Your word is my light.” Again, they attribute to the fathers the light with which to illumine Scripture, even though all the fathers confess their own obscurity and only illumine Scripture with Scripture. That is the real art, to gather Scripture correctly. The father who can do this best is the best father. One should read the books of all the fathers with caution, not believing them but rather watching out whether they also cite clear passages and illumine Scripture with clear Scripture. How could they have overcome the heretics if they had fought with their own glosses? They would have been regarded as fools and senseless people. But since they cited such clear passages, which did not need glosses, that all reason was captivated by them, the evil spirit himself, along with all the heresies, had to retreat before them.” [LW 39:164]
“Indeed, the writings of all the holy fathers should be read only for a time so that through them we may be led into the Scriptures. As it is, however, we only read them these days to avoid going any further and getting into the Bible. We are like men who read the sign posts and never travel the road they indicate. Our dear fathers wanted to lead us to the Scriptures by their writings, but we use their works to get away from the Scriptures. Nevertheless, the Scripture alone is our vineyard in which we must all labor and toil.” [LW 44:205]
JS