Hi John,
I believe that the little Porter belongs to the RR Museum of Long Island. You may recall that they sent a much larger Long Island Railroad Locomotive down to Strasburg for restoration several years ago, only to have that effort stall out due to lack of funding. This little 0-4-0 was sent down more recently and I believe it is for an operating restoration. Certainly, both the restoration and the operation of that little locomotive will be much more affordable for the museum. I think we've all see certain museums and tourist operations biting off far more than they can chew with big steam engine restorations, only to drop a lot of money into a project that never comes to fruition.
Stewart is correct in that the boiler which appears in the "riveting" scenes is indeed the NG 10-Wheeler, RGS #20, which is also under restoration at Strasburg. That one is about ready to go back together. It just needs an infusion of cubic dollars.
All of the projects that you see in these photos can be seen if you visit the Strasburg Rail Road. All you need to do is take their noon-time shop tour, which typically runs about an hour. The folks who operate these tours (including two of the ladies that you see in the photos), typically give patrons the run-down on what's going on with each project. Strasburg does have some projects for which the customers have requested strict privacy. Those projects are carried out in a building that is not typically part of the tour.
/Kevin Madore