If you're going to use a steam engine, one streamlined steam engine design has been used in a number of graphics over the years.
You can stylize that design, and it would look less Mickey Mouse.
A better idea might be to use a modern diesel freight locomotive design.
A stylized version of this would be more up to date.
I would use a futuristic TRUMP TRAIN design thinking about a High Speed rail derivative! Or maybe a Space Force derivative. When POTUS WINS BIGLY 48+ States plus gains in the Senate and retaking the House America IS GOING TO LAUNCH INTO THE STRATOSPHERE !!!
WWG1WGA!