7 Additional 2' Gauge Cars added to History

Everything that was generally know about the Mount Gretna Narrow Gauge RR was covered in Mallory Ferrell excellent assembly of the story published in the NG & SL Gazette, but it did not include the following data:
The November 1897 issue of the "Official Railway Equipment Rregister" shows that the MGNG had one flat car and 6 dump cars. There are no known photos of these two-foot gauge cars.
The roster also numbers the 7 coaches as #18 to #24 and said that #25 was classed as a Chair Car and not a coach.
Also, note that this company was owned and operated by the Cornwall & Lebanon RR, which while the MGNG was in service, came under the control of the Pennsylvania RR. Therefore, the PRR had another two-foot gauge railroad besides its tie-treating industrial line in Mt. Union, PA.
When this railroad was scrapped on 9/14/1916, everything was shipped to the W. A. Zelnicker Supply yard in Philadelphia, PA. and the 3 engines were still in his sale Bulletin #250 of Jan. 1919. Does anyone have a Philadelphia Gazetteer which might give a address for Zelnicker in the city? I wonder what is at that site today? A track foreman once told me he saw them run the three Americans up into gondolas under their own steam power, but did not know where they were going.
Anyone with other old ORER to date the rosters?