(I'm reviving this because there's more info out there now, with the rebuilding of the Barber branch.)
That cement plant you're talking about is long gone now, it's currently a junk yard/car restoration company. The tower for the plant was ripped down a few years ago and all the graffiti was painted over. In the other part of the plant is dirt and construction is going on for something, idk what though..
If they rebuild the Traylor Yard and the Barber lines, it would only serve Allentown Metal works (hills imports) like planned. Further down the line is WENZ memorials which used to have rail service, but they're selling the property, so looks like they're out of the question too.
WENZ Memorial Factory
, on Flickr
If somebody wants to see inside photos of the factory let me know :]