Since the 9200 series seems to have been discontinued in 2001, I doubt if they are still making extra barrels, but it is possible. The gun was available with 18.5, 22, 24 (rifled and smooth), and 28" barrels. A gunsmith should be able to find some, or you can try contacting Numrich Gunparts.
If it is a Mossberg, it was made by Mossberg. They did make guns for a number of "store brands".
He would make barrels. Everything was shipped and stored in barrels.
Check with Mossberg customer service for a definitive answer.
barrels
Seven barrels
http://www.mossbergcollectors.org/
A cooper makes barrels.
Coopers
Coopers make barrels.
Sorry- there was than one model 335. One by Marlin, one by Springfield. A 3rd by Mossberg is not impossible- they did make many of the Western Auto guns.
No.
Pistol barrels range from 2" to 12", and almost every increment in between. Longer barrels increase accuracy, shorter barrels make for more compactness.