Here are two Kalmbach sources:
[1] "PRR's Horseshoe Curve" appears in Classic Railroads You Can Model (2002) which was first published in 1978's More Railroads You Can Model. There is a very heavy-duty 4-track mainline trackplan based on the Andy Anderson article mix of prototype photographs and background first published in 1954.
[2] "Horseshoe Curve in the 1950s" was in the December 2002 Model Railroader with Mike Shannahan's proto-lancing for the HO Scale -- Brunswick & Tuscan. The two towns are named, Tuscan and Brunswick, with a 2-track mainline expanding to a faithful rendering of a 4-track mainline for the Horseshoe Curve including the reservoir.
I have both resources in my personal library, and arguably consider them to be the best two articles I have seen on modeling the Horseshoe Curve.
Conemaugh Road & Traction circa 1956
looking for old track plan book modeling horseshoe curve. by kalmbach. any help would be greatful. Bill