These are lots #133 (from-scratch rifle) and #134 (muzzleloader conversion) in the upcoming RIA Premier Auction. It was scheduled for April, but has been postponed – check their web site for upcoming Online Only auctions every month, though!
Barton Jenks was parts of a family rifle with inventors. These included Joseph Jenks, who was granted the first patent in the American colony in 1646 (for a sawmill design), his uncle William Jenks who created the Jenks Mule-Ear carbine, and his father Alfred who was an innovator in textile machinery. When the Civil War began, Alfred and Barton had a very successful company manufacturing machines for working wool and cotton in Bridesburg Pennsylvania. They tooled up to make rifles for there Union, delivering more the 100,000 during the war, and in the aftermath of the conflict Barton invented a rolling-block style system to convert muzzleloaders into breechloaders.
Unlike the Remington rolling block, the Jenks Model 1867 did not rely on the hammer to lock the breech, and thus was able to integrate the breech opening and rechecking into a single action. He submitted his rifle to both US military and New York State trials in 1867, but it failed to win either. Jenks did not opt to continue work on the design, instead moving to other fields and inventing mining equipment in the 1870s.