Here is the NS 3001, which started life as the Reading 3674 if I am not mistaken.
It is switching Atlas Minerals in Mertztown, PA today, just like it has for nearly 40 years.
Photo taken by my dad Jim Schlegel, employee of Atlas for 40+ years, and once known as the Mertztown yard master by the Reading operator in Topton, PA.(https://www.jreb.org/ns/proxy.php?request=http%3A%2F%2Fimg.tapatalk.com%2Fd%2F13%2F03%2F20%2Fjyju3e7e.jpg&hash=f27164351a63b9cbc704522133a4e096070d785d)
couldn't ask for a better view at work.
You are correct on the Reading Heritage... still has the drip strips on the cab roof... a Reading feature. Other Dan