@Bmurph29 -
Samuel W. Austin: According to
Maine at Gettysburg: in the listing for 3rd Maine, Pvt. Austin was listed as being on special or detached duty at Gettysburg; looks like he wasn't with the rest of the regiment there.
I found a book entitled
Pioneer Homes of Washburn, Maine by William J. Tasker online. There are 2 pages on Samuel W. Austin and the "Sam Austin House" (I couldn't find a specific URL but I had Googled <'Samuel W. Austin" "Gettysburg">; I was in Google Books. It says that Samuel W. Austin missed being at the Battle of Gettysburg but goes on to mention all the battles that he didn't miss.
There is quite a bit of genealogical information (including the fact that he married Emma Holmes of Smithfield, Maine who is possibly a relative of one of "my" soldiers). Also a picture of Samuel Austin in later years and a picture of his house. Incidentally, the other 2 Austins from New Sharon were his brothers. Not all of the book is online so I don't know if there is more but I think you'd be quite interested in what there is.
Edit to add:
This is from the Adjutant General's Report (Maine)
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