What are the markings on the pistol?
WWII Japan made one or two military type (style) revolvers, and the rest were semi-automatic Nambu pistols during the war, mostly in 8mm caliber. Single shot pistols are either antique muzzle loaders or special cartridge firing "target" pistols. Hardly no military during WWII had need of single shot pistols.
Library, internet searches.
the people who evaluate antique guns have a refence guide/book they use. they also need the gun 'in hand' to note the condition for themselves. based on their findings, they can attach a value to an antique piece..........in a lesser way, you, too, can evalute an antique pistol by securing an antique gun book and compare your pistol to the condition they list. buy a copy of "bluebook of gun values" thru Yahoo or your book store.
Hundreds. They are generally separated into revolvers and pistols (anything not a revolver) But then it becomes complex. There are different types of revolvers, such as single action, double action, top break, tip up, swing out cylinder, etc. There are single shot pistols that are top break, and bolt action. There are double and single action pistols, and even fully automatic (machine pistols). There are shotgun pistols, small caliber pistols, ones that will fit in a vest pocket, and some that have scopes and a bipod. There are antique black powder pistols and revolvers, and pistols with frames made of plastic type polymers. The study of firearms is a VERY broad subject.
possibly in quality by a little but not in performance.
Decent quality.
victor who? Need more information
Value of ANY gun will be based on condition- and in the case of an antique, originality. DO NOT clean up an antique- what you call dirt, collectors call patina. There is no way to give a value without a hands-on assessment by a person that knows antique British pistols. It may be $50, or $500.
You are aware that Ruger has made .22 caliber rifles, pistols and revolvers? You have to give information to get information.
Information not in the public domain.
Blue Book of Gun Values
currently there is one for sale on guns America they place the value at $255 here is the link, (http://www.gunsamerica.com/996720904/Guns/Pistols/Antique/P_BONDINI_45_CAL_TARGET_MADE_IN_ITALY.htm )