I predict there will be a solid niche market for new shop-built steam locomotives in the future as older machines becomes more rare. Currently, some American tourist lines operate steam locos built bran new in China and shipped to teh U.S., but China decided to completely dieselize a few years ago, so if your old steam engine breaks down, your only choice is to pay a shop to custom-build the parts, or even build from scratch.
There is currently a tourist railroad in Lancaster County, Pennsylvania called the Strasburg Railroad, which operates at least 4 or 5 steam engines. On a busy weekend they may have as many as 3 or 4 fired up at one time. The railroad supplements its income by hauling small loads of freight, which is weird to watch. A 1920's antique steam engine switching a bunch of gigantic modern covered hopper cars. They also make a good deal of cash by hiring out the services of their large and well-equipped shop, which can pretty much build an entire locomotive from scratch if need be. Lots of smaller, less well-endowed railroads around the country hire them to do work.
I could think of far worse jobs than to swing a hammer in that shop.