Rossi and Taurus. Ruger also made a semi-auto .44 mag carbine.
Gun dealers stock a variety of firearms, and can order firearms they do not have. Several companies DO make revolvers that are pink (or other colors)- but most of them are a larger caliber, such as .38 Special.
If the revolver is an RG or Rohm, it is worth about $25-50. These were low cost, low quality firearms, and frequenly had frames made of metals other than steel.
The Slocum gun was a pocket revolver made by the Brooklyn Firearms company in the mid-1860s. They are relatively rare, but not as valuable as other guns of the same era.
Gun shop, gun show, antique gun forum, or possibly Flayderman's Guide to Antique Firearms.
HOWARD ARMS CO. Tradename used by Meriden Firearms Company (1905-1918) on revolvers. Meridan was a subsidiary of Sears Roebuck and produced firearms for sale through their catalogs and retail stores.
Smith and Wesson's LadySmith line is about 100 years old has been marketed specifically for the female shooter as a smaller-framed and easy-to-use revolver, and this line is still active today. Other manufacturers have followed Smith's examples in making firearms specifically marketed for women; for example, Charter Arms has the Pink Lady line of revolvers.
First off, it's highly illegal. Second off, it's highly dangerous. Blank barrels are a much lower grade of metal than the barrels used in projectile emitting firearms, because they're not designed to have projectiles going through them. Blank revolver cylinders are typically proprietary, and do not have the same dimensions as other revolver cylinders, so you'd have a hard time finding one which aligned properly, as well.
No.
yes...
There is no registration of firearms, other than NFA licenced firearms, in Virginia.
The earliest patent for a revolver was issued in 1818, for a flintlock revolver. There were other patents for revolvers, but the most significant was the Colt patent, which issued in England in 1835 and in the US in 1836. The specific thing that was patented was not the revolver, but a revolver designed in such a way that the cylinder was rotated and locked by the action of cocking the hammer.
This all depends on the country where you live. Some countries consider them firearms. In the USA they are not considered firearms but you must be 18 to purchase one. Other countries may not consider them firearms but they are heavily regulated.