Different collectors seek different firearms. While a collector of military handguns may be interested in Lugers, a collector of Browning shotguns will have little interest. Me? I collect Mossberg, Marlin, and Remington .22 rifles. A "must have" for me is not the same as a "must have" for someone else.
No
Yes. Otherwise, there could be no legal gun dealers, collectors, manufacturers or gunsmiths in California. Dealers, manufacturers, and gun smiths must- by FEDERAL law, hold a license issued by the BATFE.
Yes, you can buy a gun online, as long as you can legally own a gun. You must comply with all state and federal laws. Once you purchase the gun, unless it qualifies as an Antique, it must be shipped to a local Federal Firearms Licensed Dealer to legally transfer the gun to you. Here is a great site to buy firearms http://www.gunsinternational.com/ Great Gun Classifieds site, over 25,000 guns for sale from Dealers and Collectors.
Gunsmiths, gun collectors, gun-oriented internet forums, you might find someone at the gun show who'll know something about it.
Try local gun shops, the yellow and white pages.
Try gun shops, gun shows, want ads, Sears memoribilia collectors.
As of 2012, there were 51,438 retail gun stores, and 7,356 pawn shops with a gun dealer's license. There are about 62,000 collectors with a Federal Firearms license.
Blue Book of Gun Values, The Parker Gun Collectors Association
look on the net for a marlin gun collectors site, they have that info.
Dealers and collectors. Start with the yellow pages under gun shops.
CHECK THE WINCHESTER GUN COLLECTORS SITE
colt gun collectors site has the info, google it