I also rode behind 425 way back when on the BM&R. Good times.
Back in 1968 and 69 the 425 was running between Phoenixville and Kimberton PA. We lived in the area and my dad took me over to ride, but for some reason it was not running that day. I was only 13 and don't remember that much about it anymore. I was disappointed though.
Just yesterday I was looking for something when I found a newspaper article I saved about 425 and that short lived operation. Seems like the locals did not like the noise and smoke and would put things on the track to try and derail it.
Look at her now. Loud and proud !
Scott L.