https://books.google.com/ngrams/graph?content=дуэлинг&case_insensitive=on&year_start=1670&year_end=2009&corpus=12&smoothing=3&share=&direct_url= - строго 0 (ноль).

https://books.google.com/ngrams/graph?content=dueling&year_start=1670&year_end=2019&corpus=15&smoothing=3&share=&direct_url=t1%3B%2Cdueling%3B%2Cc0 - больше нуля. особо смешные всплески в 1680, 1687, 1709 и 1719. так не бывает чтобы слово вошло в корпус языка, потом пропало, потом снова вошло, потом снова пропало. вывод: хвостик до 1850 отрезаем.

Lothraxi
сравните с нормальными англицизимами:
принтер:
https://books.google.com/ngrams/graph?content=принтер&year_start=1670&year_end=2009&corpus=12&smoothing=0&share=&direct_url=t1%3B%2C%D0%BF%D1%80%D0%B8%D0%BD%D1%82%D0%B5%D1%80%3B%2Cc0

офшор, оффшор:
https://books.google.com/ngrams/graph?content=%D0%BE%D1%84%D1%88%D0%BE%D1%80%2C+%D0%BE%D1%84%D1%84%D1%88%D0%BE%D1%80&year_start=1670&year_end=2009&corpus=12&smoothing=0&share=&direct_url=t1%3B%2C%D0%BE%D1%84%D1%88%D0%BE%D1%80%3B%2Cc0%3B.t1%3B%2C%D0%BE%D1%84%D1%84%D1%88%D0%BE%D1%80%3B%2Cc0

менеджер:
https://books.google.com/ngrams/graph?content=%D0%BC%D0%B5%D0%BD%D0%B5%D0%B4%D0%B6%D0%B5%D1%80&year_start=1670&year_end=2009&corpus=12&smoothing=0&share=&direct_url=t1%3B%2C%D0%BC%D0%B5%D0%BD%D0%B5%D0%B4%D0%B6%D0%B5%D1%80%3B%2Cc0