https://youtu.be/ZBtA6z5Ma94This may be the most cost effective and practical option. A 1/3rd scale Darjeeling locomotive running on 7 1/4" or 7 1/2" gauge rails.
They were originally 2 foot narrow gauge locomotives, so are easily scalable to sensible track widths while still being a proper steam train. Could probably pull 50 people.
