Where exactly was the South Paterson station on the Main Line and when did it close? Could not find any info on Google.
I'm assuming you mean the South Paterson station on the Newark Branch of the Main Line, and not the Lake View station in South Paterson that was on the actual Main Line prior to the merger with the DL&W. It was here, on Main Street opposite and a little north of Hemlock Street. Here's a photo:
Note that the building on the right in the background is still there on the other side of Main with a redone facade, and houses Bendita Arepa.
Commuter service ended on the Newark Branch in October 1966, though I'm not sure if service to the South Paterson had already ceased before that. The tracks were elevated just a few years before commuter service ended.