Thanks, Hueydoctor. The input helps us understand the history more fully.
Regarding the requirement to identify the rifle with city and state on firearms, it has been a regulation since at least April 1997. I have not yet found an older edition of the Code of Federal Regulations. At any rate, here is the relevant wording from the 1997 edition of Title 27 CFR section 178.92:
[Code of Federal Regulations]
[Title 27, Volume 1, Parts 1 to 199]
[Revised as of April 1, 1997]
From the U.S. Government Printing Office via GPO Access
[CITE: 27CFR178.92]
[Page 925-927]
TITLE 27--ALCOHOL, TOBACCO PRODUCTS AND FIREARMS
CHAPTER I--BUREAU OF ALCOHOL, TOBACCO AND FIREARMS, DEPARTMENT OF THE TREASURY
PART 178--COMMERCE IN FIREARMS AND AMMUNITION--Table of Contents
Subpart F--Conduct of Business
Sec. 178.92 Identification of firearms, armor piercing ammunition, and large capacity ammunition feeding devices.
(a)(1) Firearms. Each licensed manufacturer or licensed importer of any firearm manufactured or imported shall legibly identify each such firearm by engraving, casting, stamping (impressing), or otherwise conspicuously placing or causing to be engraved, cast, stamped (impressed) or placed on the frame or receiver thereof in a manner not susceptible of being readily obliterated, altered, or removed, an individual serial number not duplicating any serial number placed by the
manufacturer or importer on any other firearm, and by engraving, casting, stamping (impressing), or otherwise conspicuously placing or causing to be engraved, cast, stamped (impressed) or placed on the frame, receiver, or barrel thereof in a manner not susceptible of being
readily obliterated, altered or removed, the model, if such designation has been made; the caliber or gauge; the name (or recognized abbreviation of same) of the manufacturer and also, when applicable, of the importer; in the case of a domestically made firearm, the city and State (or recognized abbreviation thereof) wherein the licensed manufacturer maintains its place of business; and in the case of an
imported firearm, the name of the country in which manufactured and the city and State (or recognized abbreviation thereof) of the importer.