Basic instructions can be found in the Citori Owners manual at the link below.
If it is a Superposed model 1951.
Impossible to answer since no serial number was given.
The Browning Superposed was the first over under shotgun. It was invented by John Browning. It was produced in 1931, but John Browning actually made a model of this gun back in the 1880s. http://en.wikipedia.org/wiki/Browning_Superposed
www.savageparts.com has a schematic. I advise against disassembly unless you absolutely have to. sales@countrygunsmith.net
Rifle, handgun or shotgun?
Fine
The owner's manual provides instructions for disassembly to the extent necessary to properly clean the shotgun. Replacement owner's manuals are available on the Remington web site.
Follow the instructions in the owner's manual
The Dictionary says: "to place above or upon something else, or one upon another." As in the case of the Browning shotgun, the Superposed model ws the first sucessful Over/Under shotgun ever made. Browning used the dictionary description to name the model "Superposed" because one barrel is apon another.
best condition 1000.00$
50-150 USD
Follow the instructions in the A5 manual using the link below.