The following photo turned up in a local photo archive in central Pennsylvania.

The print was captioned "PRR steam loco awaiting scrapping stored at [coal yard along PRR branch in central Pennsylvania]." By context of other photos in the collection, we are guessing around 1945-50.

But this is IN NO WAY a PRR loco. Nothing whatsoever matches standard PRR practice--the radial stay firebox, the "candlesticks" up top, the stack, the number plate, you name it. Further, the town in question did not have a scrap yard, so it wasn't there to be scrapped.
One speculation is that it may have been en route to a scrapper (Steelton, Lewistown, Altoona area, etc.), have had a mechanical issue, and been "dumped" there to await repairs and resumed movement. But this PRR line would have been a not-very-obvious route to a scrapper, barely still being used as a through route at the time.

So, in short: Can anyone ID the loco and/or its past owner?

I can't be sure...but it might be a second hand PRR B4 0-6-0 class. 643 at Williams Grove doesn't have a Belpaire and has slide valves. The tender step appears to be like something PRR used too.

Thanks to the efforts of others on Facebook and L&N/Clinchfield/SR historian Ron Flanary, we have tentatively IDed the loco as former SR class A-7 0-6-0 1706, built by Baldwin Loco Works in 1908 and sold by SR to "Wickstrom, Inc." in January 1949.
Now, we don't know what or where Wickstrom is, but Mr. Flanary suggests it was not a scrapper or broker, as they don't appear again amongst the "disposals" list of SR steam.

Still a mystery how the loco ended up in its alleged location, however......

Somewhere on facebook recently, an individual posted a photo of a Southern 0-8-0 waiting for scrapping in Pennsylvania. Supposedly he took the photo himself in the late 50's to early 60's, so perhaps it's not too impossible that, that was the case for other Southern engines (such as 1706)?