tueday or Thursday this week would be great for a Weston tour! 6pm.good write up! while waiting outside for a meal to be prepared at Demos restaurant on Lexington St a couple of weeks ago, I spotted the train tracks of which you speak, right across from the Police Station. never knew they were there, and never thought they could connect to the rail trail you were writing about. the rail trail, which is highly ridable, can be picked up on the other side of town from Jones Rd (a very short street) off of Main St (Rt. 117). I learned about it from this forum. you can move really fast on that trail - it's perfectly flat and level. it leads to an extensive network of trails in the woods in Weston if you care to deviate from the straight and narrow rail trail.
let me know if you'd like to ride it some time - would be happy to show you!