As for the binoculars, keep in mind they were delivered in the first challenge and take another look at what the instructions say.
Sam got them for Ivanhoe and figured it out!
Here's those instructions btw
BinocularsThese provide a great view down the Darjeeling tracks. You stand at mile marker
20. Looks like everything proceeds straight ahead until mile marker
14, at which point a second line comes in and there's a switch in the tracks. Also, looks like there's a small station at mile marker
16. Down at mile marker
12 the two tracks merge into one. That's about as far as you can see.