I missed the B&LE 643 the first time through. I finally saw it through the weeds. 
Whose former tracks does the Pittsburgh & Ohio Central run on? I haven't heard of them, but saw the familiar G&W company paint scheme since I live in Butler near the B&P engine shop.
Mark, here's what I remember of the 2012 September issue of TRAINS and from my own research. The Neville Island remnants were PRR originally, as was the line to Arden (PRR's Washington, PA branch). The POHC also owns part of the former PRR from Duff Junction next to the Ohio Connecting bridge to a point just outside of Walker's Mill (near Rennerdale). This used to be the Pittsburgh to St. Louis "Panhandle Line," now partly a busway, the POHC (serving one customer, I believe) and the Panhandle trail. From the McKees Rocks area and its split with the Panhandle close to Walkers Mill, to Junction #1 (no longer extant) the Washington Branch was actually two ROWS, one owned by the PRR and one by the (eventual NYC subsidiary?) Pittsburgh, Chartiers & Youghiogheny shortline, which the companies ran as a double-track mainline until the end of PC&Y trackage near Bridgeville. Conrail controlled both companies up until 1996, at which point they were sold to the independent Pittsburgh Industrial Railroad company. In 2000, the line was bought by the deceased Jerry Jacobson's Ohio Central, which itself was bought by G&W shortly thereafter.
PIR's most famous motive power was a pair of SW units that MTH did a run of in PS2 about ten years ago, and a dummy unit on a flatcar about 6 years ago. I thought I remembered at least one unit being an SW1200RS, and that they also had a pair of GEs that were not repainted and/or were leased, but I have not found the source for that information again yet; the extant online sources say that both units were SW1500s. POHC may have retained ownership of the units and supplemented them with a blend of GP10 rebuilds and other endcabs; with the Genesee & Wyoming acquisition of the OC, the PIR units were dispersed to other G&W properties (CIND and CSOR for 2342 and 2340, respectively). Up until about 2015, power on the PIR was solidly Ohio Central colors, with at least two (and possibly more) units lettered for Pittsburgh & Ohio Central, mostly consisting of GP10Ms, an SW1500 or two, and a GP38-2. Starting in 2015, G&W slowly started subsuming P&OC into the Ohio Central identity. They received an OC genset in 2015 in orange, which I believe was sent packing this summer. 1711 was repainted into G&W colors, but still recieved POHC lettering. 706, the other GP10M, was still in original paint when it was retired in 2019ish and sent to LTEX. The last POHC unit in maroon was an SW1500, which I believe is now also gone (as seen in the video, its stacks were capped). Currently, the only POHC-lettered unit is 1711; the two ex-Southern GP38-2 rebuilds are OC transplants and lettered as such. Replacing the other SW1500 and the genset in recent months has been the original PIR 2342, now relettered for CIND and still sporting faded PIR paint (which I caught earlier this week). The other PIR SW1500 is, as of 2019 per a video I watched, still on the CSOR in its original colors.
Here's the federal sale notice:
https://www.govinfo.gov/conten...-27/pdf/96-32962.pdf
And here's a more recent narrative that the Trolley Museum just put out:
https://pa-trolley.org/educati...iers-valley-rr-line/
