And, here's the meaning of the crown and VR stamp on the buttstock:
"This mark was added in 1863 after the rifle had been withdrawn from first line service and sent to the War Office Refurbishing Depot at Pimlico in South London, the site of Colt's old London factory. There, it was overhauled and received various additional inspectors' stamps on the barrel of a crown over P and a number. The rifle was then downgraded to Second Class and reissued to the Rifle Volunteers who retained these arms until the winter of 1869/70 after which they were sold off to the Trade. The opposed broad arrow stamp defacing the Pimlico stamp of 1863 was added when the rifle was sold out of service after 1870. There is absolutely no chance that this rifle was ever involved in the ACW. "
SCL