Your question, as it is asked, makes no sense. The 9mm cartridge wasn't invented until the mid 1890's.
I do not believe that Winchester ever made a 9mm shotgun, although 9mm "snakeshot" ammo, comprised of tiny pellets and looking lot a shotgun shell exists. Do you perhaps mean 9 guage?
Fiochi
9mm Largo is 9x23, but be careful not to confuse it with the 9x23 Winchester. They have the similar dimensions, but the 9mm Winchester cartridge is loaded to a higher pressure and is not safe to fire in a pistol designed for the 9mm Largo.
Winchester
This isn't a Winchester serial number.
Midway USA carries fiochi 9mm rimfire shotshells for the Winchester model 36 they are on the clearance page so I am not sure if they will continue to carry them.
The weight of a lead sphere that fits the bore determines the gauge, except for 410 and 9mm
While I cannot say for sure if you can or not?I would suggest that you try Old western Scrounger first.Then maybe look at Gunbroker.com,or guns america.Both web sites might have a listing for the 9mm winchester magnum ammo you seek.
No. There are more than a dozen DIFFERENT "9mm" cartridges, and they do not interchange. The most common is 9mm Parabellum- also known as 9mm Luger or 9x19. It does NOT interchange with 9mm Kurz, 9mm Corto, 9mm Makarov, 9mm Ultra, etc.
No. There are several different calibers that are called 9mm. These calibers are not interchangeable. A quick rundown of 9mm pistol cartridges: 9x17 also called 9mm Kurz, 9mm Short or .380 Auto 9x18 Makarov, also called 9mm Makarov 9x19 also called 9mm Luger, 9mm, 9mm Para, 9mm Parabellum 9x21 also called 9mm IMI 9x23 also called 9mm Long, 9mm Largo
9mm MKV is not the same as 9mm Luger.
The .380 IS a 9mm- a 9mm Short (also called 9mm Kurz or Corto). There are more than a dozen different 9mm cartridges. Most people mean the 9mm Parabellum (also called 9mm Luger) when they say 9mm. The 9mm Parabellum IS a longer cartridge than the .380 .