I believe that your Selectric actually used Prestige Elite twelve pitch, not Times New Roman 12 point. That's what mine uses. Looks remarkably like Times Roman.
Times Roman is a proprietary face, and so is Times New Roman. They are copyrighted by the designer. Times New Roman is copyright 1988.
Times New Roman, designed in 1931 by Stanley Morison, Typographical Advisor to the Monotype Corporation, with the assistance of draughtsman Victor Lardent.
The Times of London first used it the following year. Linotype and Intertype quickly licensed the design, changing its name for their marketing purposes to Times Roman. Times Roman became an original core font for Apple in the 1980s and Times New Roman MT became one for Windows in the 1990s.
(Ironically, at the same time IBM invited Frutiger to adapt Univers for the Selectric Typewriter, they asked Morison to do the same with Times New Roman.) Whether superior to Courier or not, neither of these digital renditions of Morison's original design is the best one available today-in the opinion of information design specialist Erik Spiekermann. That honor goes to a version called Times Ten.
State Department bans Courier New 12, except for treaties-AIGA Journal