One piece to the puzzle: the crown-over-V mark may be German. As I understand it, the Germans passed a proof law in or about 1891 requiring firearms to be proved. Some or all firearms that had already been manufactured were grandfathered and marked with the crown over V mark, the V standing for Vorrat or "on hand."
During the Franco Prussian war (1870-71), the French bought tens of thousands of U.S. arms, including Spencers (rifles and carbines, models 1860 and 1865) as well as Peabodys and many other types. The Peabodys were captured by the Germans en mass--many apparently before they were issued--and apparently made their ways to German arms dealers, where (if still in stock in 1891) they were marked with the crown over V. These rifles are fairly common. At least some Spencers traveled a similar path, and your 1865 appears to be marked as such.
Attached is a photo of the markings on a Peabody courtesy of Keith Doyon found at
http://www.militaryrifles.com/Peabody&M/GerFrSpanPeabody.jpg that illustrate markings on a Peabody that appear similar to those on your Spencer.