The gun was made in 1966.
Looks like the serial number to me.
Yes it is illegal to own a gun that does not have a serial number. It is also illegal to remove the serial number off a gun.
It depends on what you mean. If you mean that you want to find the age of the gun based on the serial number, there are a few online sources, such as the Blue Book of Gun Values. If you mean that you want to find out if it is registered, no.
With just the serial number, nothing.
It would be almost impossible to identify a gun just by its serial number.
First, I think you mean register. In MOST of the US, there is no requirement to register ordinary firearms. Now, about the serial number- it is unlawful to REMOVE a serial number, or to possess a gun that has had the SN removed. However, there are guns that do not HAVE a serial number, and they are legal. Rifles and shotguns made prior to 1968 were not required to have serial number. Those guns are listed as NSN- No Serial Number- on paperwork that asks for a serial number.
Just by the serial number, no.
Impossible to answer. A serial number is not unique to only one gun in the world.
Impossible to date a gun with just the serial number and no other informaiton.
The serial number is on the frame.
You find a published list of serial numbers for the maker.