It looks like you had a very nice hike along this trail!
Let me see if I can straighten out the railroad history for you.
The Burlington and Mount Holly Railroad and Transportation Company received its legislative charter in 1836, but the company became moribund from the effects of the Panic of 1837, so little or no work was completed. In 1848, the state legislature passed supplemental acts to the original incorporation, allowing construction to begin. As built, the line extended from a wharf on the Delaware River in East Burlington, near the present-day Curtin Marina, southward to Mount Holly, terminating near Grant Street. Here the company had an engine house, a station, cattle pens, etc. In 1857, management determined it would extend the line to Pemberton and received a legislative charter for the Burlington County Railroad and it is a portion of this route that you hiked. In 1865, the Vincentown Branch of the Burlington County Railroad received its charter. Then the Camden & Amboy, as the parent company and source of funding for these lines, decided it would extend the Burlington County Railroad to Camden and chartered the Camden & Burlington County Railroad in 1866. The line to Medford from Mount Holly was built in 1868-69. Eventually the line leaving Mount Holly for Pemberton branched off at Birmingham and reached the Jersey coast at Barnegat Pier and extended out across the bay on a long trestle, which burned in 1944.
The electric car you link to in your posting represents the very first experimentation in electrification in which the Pennsylvania Railroad engaged. The company constructed a powerhouse in Mount Holly and strung trolley wire between Mount Holly and Burlington and operated these cars. The electric service only operated for a year or two before the powerhouse burned down and management decided not to rebuild the generating station. It was from this little experiment that the electrified Northeast Corridor grew. This car, however, never operated on the portion of the line that you hiked.
Yes, the station is the same one viewed in the post card on the West Jersey History Project. The two-story building to the right of the station served the line going to Burlington.
Let me know if you have any other questions.
Best regards,
Jerseyman