No. Ruger is a brand name. Generic means no brand. Contradiction in terms.
I do not believe the RG 14 is a Ruger. These were inexpensive German made handguns (Rheinmetal Gemeinschaft) that sell for $25-$50. IF your firearm is marked RUGER on the barrel or frame, I could be wrong. If it is marked RG, not a Ruger.
Many different brands.. Too many to list by model. Popular brands which manufacture handguns in the US include Springfield Armory, Ruger, Colt, Smith & Wesson, Kimber, Les Bauer, and others.
Unless I have missed something, All Ruger firearms are made in the USA. Other makers brand forign made guns. But none of Ruger firearms are forign made.
1970's Gun Digests
Go to the Ruger website, Customer Service, Historical Data, Handguns, find your model, and there is a serial number/year table.
Fail to understand the "so called" part of your question. Yes, handguns made in other nations are imported into the US by a Federally licensed importer.
The most current year that data is available for is 2005. In that year, US manufacturers produced 1,088,827 handguns. Not quite 3,000 per day. That does not count handguns that are made outside the US and imported. Nor does it count handguns that are legally made by a private citizen for their own use, nor black powder type firearms.
I doubt that there are 16 different TYPES of .45 caliber handguns made in the US. You will need to define your question a bit- revolver or auto pistol, which .45, and how YOU define "controllable".
Go to the Ruger website, select customer service, historical information, handguns, your model, and check the serial number table.
Go to the Ruger website, click Customer Service, then historical data, handguns, your model- and there is a serial number range list for different years.
Colt, S&W, Ruger, Wilson, CZ, Beretta, Baikal, Walther to name a few.