Here are some views of the 'John Armstrong' I finished in the Spring of 2011 after so many idle years of other hobbies like restoring Model A Fords and '57 Chevys and working on pocket watches. Notice I used the correct barrel-retaining key method on this one--much more time consuming to do. Both this gun and the one you are selling I'm certain feature Douglas barrels (no longer made as of years ago).
Larry is also the maker of another Armstrong Style Rifle shown here. Additional copy by Larry on that rifle has been added.
Photos and copy supplied via Tim Hodges.