Saw this on the St. Louis Post-Dispatch website:
Movers, shakers and more than a few steelworkers in northwestern Pennsylvania will on Friday dedicate a miniature replica of our burg's most famous landmark outside of the Warren County visitors' bureau — and deservedly so.
Warren, Pa., is home to Pittsburgh-Des Moines Steel Co. (PDM), which fabricated about 80 percent of the steel used for the iconic outer skin of our monument. About 280 members of Boilermakers' Local 659 worked on the project between 1962 and 1965.
The article goes on to say that the replica is 14 feet tall; since the real thing is 630 feet tall, that works out to 1:45, or about O scale. (For reference, 4' 8/2" in 1:45 is 1.256")
Link to the article (with pics): http://www.stltoday.com/lifestyles/columns/joe-holleman