Hi CSRRfan86.
Honestly i couldnt tell you. I live right on the tracks basically, they Newburyport Branch portion of it crosses my street. I know that there are still portions of the track that remain. In some areas you can even see where the ROW used to be. Part of it is now a street. Here is a link to an awsome site that has way too much information and a ton about the South Reading Branch.
http://www.oldrr.com/ This site has almost every RR line you can think of (except the Conway Branch
) Btw, how do you know of the South Reading Line?
Here are some pics that I took of the line (Newburyport Branch/South Reading Line)