Wrong gauge I know, but the Strasburg Rail Road occasionally runs real mixed trains hauling revenue freight and (a few) paying passengers (about 1/20 the number that chase) as shown in this YouTube video. Our diesel was in the shop, and NS forecast sending enough loads to require two engines. As it turned out, one would have been sufficient, but it still makes a very good video.
We had been running steam mixed on a regular basis, but NS got to be too unpredictable as to when they would deliver to us, making the run impractical.