A video of my Trainorama !

[Doodlebug]

What a fun and charming project!  So much nicer than trains stuck in display cases.
A small suggestion.  Use leds light-beam sensors (or even small track-level microswitches) to sense trains nearing end of track and ramp the speed down then reverse and ramp up again.
Easier on the motors and the eye...  Relatively easy to design, unless these engines are all controlled digitally already.
-Jeremy

Thanks for those nice words , Jeremy. I have never seen this type of running layout before
so I thought it be a nice tribute to the age of steam.

I also considered hall effect switching as well as your idea.
The speed is now manually PWM regulated so I could do as you suggested.

But this originally was just to be a quick project and then get on with others.....
…..I'm 86 so don't have much time left !