L&HR bridge traffic

[JBnWaverly]

Hello Group- If I may take liberty with the vast amount of LHR knowledge in the forum and maybe lighten up a bit on the constant barrage of economic news. I am in the process of "rightsizing" recent rolling stock acquisitions for use on my future venture into HO version of LH. Looking through available archives and the excellent Morning Sun book, I am trying to get a handle on the bridge traffic carried by the L&H in the late 60's through Conrail takeover. Now that I have glasses and able to actually see the unbelievably minute details printed on todays rolling stock, I have found that some of my pieces were ahead of the timeframe I am modelling. Can someone clue me in as to why some far off roads appear in some of the photos? I see ATSF, NP, SP and UP in many of the photos. Was this just a coincidence, or was there a percentage of bridge traffic from roads far from the northeast and DelMarVa region? Also, I do get the prevalence of covered hopper traffic due to Limecrest and zinc mine shipments, but would LV be most appropriate for this traffic? I am planning on taking some liberties with the Port Morris traffic for the timeframe, but what would I have expected from pre-merger EL interchange if I were to model representative roads coming off this line? Last question, where did the coal trains originate from and what was their destination? Thanks to those who can steer me through my "outsourcing project" and hope this doesn't sound too gimme-gimmee, I am just running out of sources for research on my own. Thanks again, JB