Unknown. There are a dozen or so big makers and a lot of smaller ones that don't get reported becasue they don't have to.
In the US, the BATFE.
You will have to be a little more specific. Are you talking about companies traded on the stock exchange? Companies with more than or less than 25 employees?
No, but you need to be the legal owner of that firearm.
No way for us to tell from a serial number alone. Serial numbers are NOT unique to any one firearm.
it is a number
No such firearm model number
If it was a firearm originally manufactured without a serial number (serial numbers weren't required on firearms in the US until the passage of the Gun Control Act of 1968), then no. However, a firearm which originally had a serial number and had it removed - very much illegal.
535
435
33,524
100
The value of any firearm is based on exact make, model and condition. You gave us one of the three things we need. Serial number does not tell us the model or condition.