The Alco RS-1 is my all-time favorite engine. I just love its sleek looks. When I re-entered the hobby in 1999, after buying an N-scale starter set, my first "real" purchase was an Gulf, Mobile & Ohio RS-1, purely because of its looks. Later, when I decided to model the mighty Pennsy, I bought several Atlas RS-1s. So, when I switched from N-scale to S-scale in July, 2008, I knew I had to have one. I eventually stumbled across the Railmaster Hobbies web site and their RS-1 kit. I decided to model road number 5627, which was a PRR AS-10am (Alco, switcher, 1000hp, modified design, and multiple-unit equipped) that was delivered to the Pennsylvania Railroad in June of 1950. There is a good 3/4 profile view of that engine in the book Pennsylvania Railroad Diesel Locomotive Pictorial Volume One. The kit took me three months to build. The final model weighs 2 pounds and 4.4 ounces (1.035 kilograms).