You can ask specific questions here. Your local library should have a copy of Flayderman's Guide to Antique American Firearms which covers everything up to 1900. Once you find it, look at all the other books on the same shelf.
Not a lot of information. It was a trade name retailed (I believe) by H&D Folsom of New York City. The guns were made by Crescent, Crescent-Davis, and/or Stevens c. 1890-1940.
What kind of information?
One would be able to find out more information about m4 airsoft guns online on Amazon. Two other sites that have some information about m4 airsoft guns are wikiHow and HobbyTron.
You can find information on when these guns were manufactured on OldGuns.net.
Need more information, such as type of firearm, etc.
Try e-gunparts.com
Look on Nerf.ea.com to find out more information
Is it "WILSHIRE" or is it "WILTSHIRE"? I have no information on Wilshire, but WILTSHIRE is a known trade name used by the HD Folsom Company on guns they sold to a major hardware/catalog store in New Orleans LA from c.1890-1910. Is the gun break open or muzzleloading? sales@countrygunsmith.net
One of innumerable guns imported from Belgian from around 1880 through 1910 for the catalog/hardware trade. Value would be below $200.
Information on 45 caliber guns is available on websites that sell guns, for example Cabelas', and also websites of arms organizations such as the National Rifle Association. Information is also available at the website The Gun Zone.
Gun Broker
Branquart guns are high-end Belgian 'best-quality' guns and need to be individually appraised.