I would like to know if you guys could help me with a question I have about the Panzer IV J.
Did the Panzer IV J's have smoke discharges on their turrets and if so, where?

They don't have any. The reason for this is that a small close combat weapon, a sort of small mortar was built into the turret roof on the loaders side. This could be loaded with either smoke or explosive cartridges. If you look carefully @ a Tamiya J, you can see this moulded on - it's a round projection with small circle moulded on it - inreality this is the muzzle of the weapon. I can't remember what it's called.

Go here for the Nahverteidigungswaffe...

http://www.custermen.net/nahvert/nah.htm

good am,
regarding Ausf. J could also be a periscope installation for the t.c.
J. also the Schurtzen installed-kind of a tight fit for anything else.
cheers
c6o
carpe diem