reply to u/Fireflystudio at https://old.reddit.com/r/typewriters/comments/1xn596e/remington_identification_help/

They (the serial number prefix JT) sort of appear at https://typewriterdatabase.com/remington.42.typewriter-serial-number-database but as J, SJ, and EJT.

You'll find two of them on https://typewriterdatabase.com/Remington.Standard.42.bmys. Your serial number seems to line up with the other Italian made ones, but the database doesn't seem to have any detail about years of manufacture for those serial numbers. Because they're fairly serious collectors who've listed theirs as early 1960s models (196X), yours was probably also early 1960s. The shift from the green keys to the white/gray chicklet design can be seen at the break between 1959 and 1960 for the Remington Quiet-Riter Eleven: https://typewriterdatabase.com/Remington.Quiet-Riter+Eleven.42.bmys

Presumably the primary prefix model letter for the Remington Standard is "J" and the additional letters either indicate the factory/country of manufacture or other functionality. (Remington often added the letter "T" to some models to indicate tabulator or decimal tabulator, though in this case, as a standard, a simple tabulator would have been implied. Perhaps in your model's case the "T" stands for Torino which is likely the plant it was manufactured in in Italy. See also: https://www.nytimes.com/1951/10/08/archives/remington-rand-to-build-in-italy-company-to-construct-large-plant.html

The SJ models seem to be from England, FJ models in France and another CJ model, potentially from Canada? Some additional research ought to uncover if this hypothesis holds.

Torino, Italy