I don't have dates for you, but I can offer this - see 14 CFR 121, sub part N, O, And Y and also Appendicies E, F and "H" I believe. Way too many accidents involving training flights and large Part 25 aircraft until rule making pretty much made FSTD use mandatory under 121...

At the end of each section/sub part/appendix is a listing of the Docket numbers and dates they were originally published. It looks like somewhere around 1970... If you are able to pull up the Docket, look at the PREAMBLE to the rule. Lots of good info there...

If you really have a lot of time on your hands, research
Advisory Circular AC 120-40 and 14 CFR Part 60. The Appendices of Part 60 are about 500 pages, all about FSTD's.

FSTD = Flight Simulation/Training Device and includes Full Motion Simulators(Level A,B,C,D) and Flight Training Devices (Levels 1-7)...