The value of a Japanese soldier's rifle from World War II varies on model and condition. A paratrooper's rifle in good condition might be worth as much as a $1,000. Most other rifles of the era are worth less than that.
If its in good condition, it could go for $1500 or more (as of February 2015). If you happen to have one made by the Sewing Machine Company SINGER, it could fetch quite a bit more money.
During WWII, the government had several companies make arms for the war effort. Some weapons made by smaller companies are quite rare and expensive!
Depends on model and condition. Sort of like "How much is a Ford car?"
Yes, some of the remington tubes will but not all. I have a remington modified choke in my mp 153 right now.