Hello, this thread is incredibly useful.Not sure if its any help, but at least this Iyama manual has a schematic using the 1888FTC and its pinout, etc...on page 73 I think. It might be of some use to compare with the datasheet you found.
https://mega.nz/file/Pg0z1axC#O3GlQcMHgGJnkE8Nl2tQXNbAyzu-EdQagwKRvGwQEzs
If I get a chance, I will read though this. I used ot be able to tell ya how what every component in crt monitors were for and ho they operated, etc...I could have at one point drawn you an schematic so you could out together a working monitor, but alas, no more It will take some time for it all to come back to me.
Could you share the Iyama manual again. The file is no longer available. Thank you!