I noticed some stuff that didn't make sense regarding the path the guys would've made to get from Dannemora to Lindley to Friendship so I will go ahead and re-post this map that shows the likely path, which of course presumes they're riding the rails on freight trains as often as possible:
There is no doubling back IMO AFAIK.
I LOVE this map! Actually, I think there was some doubling back, if all these sightings were accurate. When they got to Gangs Mills, the line goes in two directions: 1 line heads south into PA, and the other heads south for a few miles, but then starts heading west. I think they got on the wrong train (if their ultimate destination is Buffalo), and took the Pennsylvania train by mistake. (Wonder if they have maps of the railroads or even just a NY map??). So, probably, when they got as far as Lindley, they realized they were going in the wrong direction, and had to get off that train and catch a northbound one back up to Gangs Mill. That was probably when they were spotted in Lindley.
So, then, when they got back up to Gangs Mills, they got on the westbound train, which follows the Canisteo River. When they reached Hornell, there's another train yard, and I think they might have gotten on the wrong train again. Next to Buffalo Street in Hornell, the track splits, and one track heads northwest toward Buffalo and the other drops south and then starts heading west, sort of following Rte 417 for a little while, and then starts paralleling I-86/Rte 17. That would bring them right into Friendship. By this point, they may have been getting worried that they were on the wrong train, and gotten off (and then been sighted). Actually, if they just stayed on the train for a few more miles west, when they arrived in the village of Kill Buck, there's a line there than runs north to the Buffalo area.
GGE, you made an interesting point that Matt may have been headed to Buffalo for his birthday on the 25th (sure that will thrill his relatives). Didn't Sweat just have a birthday? Wonder if he were in Bham by then?
(Hope this all makes sense. Keep nodding off while writing - need...a....nap)