The problem with getting Moses' autograph

As an Evangelical Christian my belief in the inerrancy of Scripture is important. Often times Evangelicals will defend the viewpoint that the Bible is without error by stating that the original written revelation is inerrant, but that the copies which were made afterwords may have suffered in some way through copyist errors. It is important to realize that these "errors" are extremely marginal and do not impact significant doctrine. Often, we are talking about variations in spellings of proper nouns. These originals are called autographs. It is easy to conceive of an autograph of Romans for example. Paul and his amanuensis (secretary) sit down to write the letter. The letter is copied multiple times. Paul probably has a copy made for himself. The early church makes multiple copies to preserve it and so on and so on. It is easy in this case to understand what the autograph of the epistle to the Romans looks like.

But what about some of the OT books? Take for example the book of Deuteronomy. Scripture is replete with statements acknowledging Moses' authorship over the Law. Much of the book of Deuteronomy is from Moses' first person perspective. It seems natural to read the majority of the book as if Moses is indeed the author. That is until we get to the final chapter. In ch. 34 Moses' death is recorded. It is obvious that someone else has written this part of the book of Deuteronomy. Possibly it was Joshua, but we don't know. Whoever it was didn't leave a signature.

Here is my question: what is the original autograph of Deuteronomy? Is it Moses' work in chs. 1-33, or is it the finished edited version of chs. 1-34? My opinion is that chs. 1-34 is the version we want, but if this is correct, then we are looking for something different than the original which Moses penned. Imagine if we found chs. 1-33 and were completely persuaded that it was Moses' original autograph. Would we throw out ch. 34 as uninspired? Probably not.

My point in this post is not to rattle our faith, but to help us to think through the sometimes 'pat' answers which we give those who wrestle with inerrancy. In this case defining what we mean by "the original autograph of Deuteronomy" is difficult to conceptualize. Thankfully God is great enough and powerful enough that despite our inability to conceptualize what an autograph is, He can preserve His Word to us that we may believe in Him and enjoy His grace.