To answer your question much of the grade was completed on the Montclair end. A tunnel was to be built through first mountain in Montclair and Verona. The cut leading to the tunnel was visible until around 1989 when MKA built their field in the area of Upper Mountain an Claremont Avenues. The exit to this tunnel would have been in the area of Annin Flag in Verona, part of the grade from Annin Flag to Verona Park still exsists in Verona to this day, however brush and trees have taken over in recent years. The most notable remnants are in Verona Park, Duck Island as it's called by locals was built as footing for a trestle that would have spanned the lake from an area on the hill behind the playground to the large embankment in the area of the church on Lakeside Avenue. The tunnel was abandoned in the "Panic of 1873". There was hope for several years that the line would be completed when the NY and Greenwood Lake Railroad took over the right of way, however in 1892 the railroad came via a different route on what is now known as the West Essex Trail Connecting with the Montclair and Booton Line at Great Notch running to Essex Fells I do not know if this connected with what is now the Morristown and Erie RR's line running through East Hanover and into Roseland.